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Safety Program Accident/Incident Investigation
So, welcome to you all to this particular class. So, this class is primarily on accident
investigation. We can also interchangeably people use as a incident investigation, so both are
almost the same. If you want to have zero accidents in site, primarily you have to attack all the
incidents. Incidents when there is an impact it has an accident otherwise with no impact is a near
So, if you want to achieve a zero accident and a very safe construction site, primarily all
incidents should be investigated. So, we can term this as incident investigation or accident
investigation both are colloquially same.
(Refer Slide Time: 00:59)
So, why should we do accident investigation, how should we do accident investigation all we
will discuss in this particular class. So, what do you mean by hazards, just brushing up from the
previous week's lecture. So, hazards are the dangerous situations or conditions that can lead to
accidents. So, construction site generally it has so many hazards and these hazards are always
challenging even for a skilled experienced worker also.Because sometimes the situation may not be the same. So, the earlier technique that you use to
eliminate or safeguard the hazard will not work in every situation. So, hazards always pose a
serious challenge to workers. And many workplaces have high accident incidence rates and
accordingly they also have a high severity rate because of these hazards. So, hazards should be
discussed in the sense hazards primarily they are the root cause for any accident but that does not
happen every time.
For an any event to be called as an accident, there should be some following characteristics.
Number one there should be an outcome and if the whole incident itself is like planned even by
knowingly you know that one equipment is not working, but still you want to operate that
equipment, it may create danger to yourself or to your coworkers. Then actually it is considered
to be a crime and it is not treated as an accident at all.
So, that should be kept in mind in the workers and in the construction personnel. So, the personal
injury or property damage may result as an effect of an incident, so this accidents has to be
investigated. An occurrence of accidents also differs from site to site, because the nature of work
itself varies or even if the work is similar in nature environment may vary. For example, if you
wanted to do tunneling, you may cross so many barriers and so many obstacles.
So, the physical way of executing the work progress itself will differ based on the challenges that
comes in forth. Different types of hazards emerge in the project, because the project is generally
unique and challenging. An unsafe people involved in executing the construction activities, that
is also a common factor which we have seen in the last week's class also. So, most of the
accidents are actually linked with unsafe activities of the workers available in the site. So, just to
have an idea on what are the causes of accidents, and what are their effects.
(Refer Slide Time: 03:50)So, causes, you can start from carelessness of the work nature, even though you know you have
to take care of all precautions, and how to execute the work. Sometimes it goes off your mind
and you are careless, and negligence to follow safety rules to follow all procedures. So, that is
primarily one of the reason and it is also ranks number one in many of the construction sites.
Unsafe working conditions, for example dropping or throwing materials from high rise
Just because you do not want to come down or pass on the material through different ways like
chute or something. So, dropping, so that is primarily an unsafe working condition or practice.
Failure to follow safety rules, primarily if there is an improper way of operating an equipment or
improper way of executing of construction work, or it can be operating a defective tool or
These are all failures to follow safety rules, even failure to wear PPE is also one of the violations
in safety rules. Improper use of safety items, for example scaffolds or faulty ladders, the way
scaffolds are used in construction sites, all these can be examples. Now if you see here workers
are the primary party who are affected because of any accident or injury that we have seen, but
who are the primary contributors?Again some statistics and analysis was conducted, and during the survey, it was found workers
were the main contributors in contributing to an accident. Now whether there is an incident or an
accident or in the severity or impact of the accident, keep that aside, but what about the effects of
all these accidents? Number one will be time lost on project execution, so you just have to have a
break to come back to normal on the incident or the accident consequences.
Then productivity loss, if the severity of accident is too high, then you may have a complete stop
or nil work in the entire construction site premises. So, thereby you may also have productivity
loss. Then cost, medical expenses, treatment, recruiting an alternate worker with for the
compensation, then training etcetera, then cost on the accident investigation, time, effort,
personnel. So, all these are unnecessary cost as a result of accidents, so accidents has to be
Reputation of firm, psychology of workers that every time the workers start feeling that they are
always unsafe in a workplace that psychology can also make them demotivate, less productivity
and so on.
(Refer Slide Time: 06:43)
Now what do you mean by accident investigation? And why should you do accident
investigation? So, now we are into the topic now, so it is important to investigate all accidents,
regardless of it is impact or effect that is what I said. Even an incident should be investigated because sometimes you may have an impact, no impact as a near miss but you you cannot keep
quiet as a result of the same.
Because some unnecessary event has happened, some unwanted event has happened which you
should be really looking at in analyzing and investigating. So, that is what I said colloquially, in
this particular topic you can use the words incident and accident together. And accident
investigation in many of the safety and health programs, it is a main component. And it is an
very important element because if you want to have a zero accident in a site.
Or if you want to have a complete safe construction site, then you should be having accident
investigation as one of the key programs. Because that will help you to analyze the causes of an
accident and identify the problems are mesh ups in the way construction work has progressed,
and helps you to put a stop to all these unsafe practices in the sites. So, what do you mean by
So, accident investigation is nothing but a procedure to find the causal factors of an accident
without finding fault or blaming on someone. Obviously when you are digging out the causes of
an accident and going in depth, obviously you may have to point out on someone for a fault or a
defect. That somebody has done something, so it may obviously be cornering on someone. But
the main purpose of the investigation should not be necessarily in terms of blaming someone, but
it is only to avoid any such future accident, so that should be kept in mind every time.
So, what is the main purpose of accident or incident investigation is to prevent a future
occurrence, is to prevent a future accident. So, again if you break down that, avoid spending
money on accidents in the future which is unnecessary.
To find out why the individual violated the safety policy, maybe there was a head injury, the
workers did not wear hard hats, fine. But why did the worker violated that safety policy and did
not wear a proper PPE, that should be really investigated and rather than punishing the worker
for not wearing the PPE. And when accidents are not reported or they are investigated and
analyzed, what happens is?The basic cause for which this particular accident was triggered will be still there and it will not
be corrected or rectified or modified. And what happens is it always allows or gives a chance for
a future accident to happen any time of the construction work. And next time it can also be very
dangerous or very disastrous as an outcome. So, you want to avoid that then a very small an
alarming call, you should take it up very seriously and investigate the accidents.
(Refer Slide Time: 10:01)
So, let us continue with, the steps involved in investigating an accident. So, number one is report
the occurrence to a designated person in the organization. First of all you should know whom
should you report to, and before that you should also know what are the occurrences which you
should report , this we have discussed in the last week class itself. Any death, or a major lost
work day cases or resisted workday cases, everything should be reported.
Sometimes if an organization wants to have a zero accident site and their goal is to achieve that
as a very serious goal. Then even near misses and even health issues everything has to be
reported. So, during the training and in the safety meetings and safety talks, you should be very
clear on what should you report, what point of time, primarily the point of time is just
immediately you have to report.But what are the issues that you should report and bring it to the knowledge of the higher
officials that you should know a priori before you start working in the construction sites. And
you should also know whom should you contact and report to? Then provide first aid and
medical camp to the injured worker or the team, whoever has got injured. So, more than going
really serious into the accident investigation, you should first put off all the dangers, maybe an
equipment has run in (()) (11:29).
First you stop the equipment and so on, and give first aid and medical care to the injured
workers, inform this to the higher officials. And the general steps by the incident investigation
team will start. And those steps are the scene management primarily is to just get the idea of the
entire site scene. Then witness management, you can also look at who the workers who were
working close to the injured worker, other workers, what happened all pictures, photographs,
measurements, videos, everything you should be able to do.
Then investigate the incident and try collecting data by interviewing so many people and so on.
Then start analyzing the data and identify the root cause. So, you should look at the same
accident or incident in a multiple perspective to identify the real cause for such an incident.
Otherwise, it will be this worker operated the equipment and hence this accident happened, and
you will be going only to the unsafe act or condition which just triggered this accident.
But you should again go back to the indirect causes or the basic causes of why this accident had
happened. Report the findings and recommendations, all these has to be part of the incident
investigation personnel. Now once this report is completely done and all angles are analyzed and
so on, then the construction organization will have a proper plan as to what should be the
corrective action, how should you implement the corrective action and see what is the effect of
that corrective action.
Maybe sometimes some corrective action may not rectify the hazard at all and still a very serious
issue may also happen. So, you have to also evaluate the effectiveness of a modified course of
action under corrective action and make changes for continuous improvement.
(Refer Slide Time: 13:23)So, that is primarily as a PDCA cycle that has to be done. The first step is a prompt reporting of
accidents. So, now if the prompt reporting of accidents itself did not take place, when your
accident investigation itself will totally collapse. And as I told what should be reported, one
should know and any worker or site supervisor should also know whom should they report to,
and what are the incidents that they should report to?
And prompt reporting it is very compulsory for any accident investigation to go in the right
direction. Now sometimes what happens is, this prompt reporting of accidents itself will not take
place in many construction sites. There are several reasons for workers not reporting an accident
, let us discuss the reasons. One is fear of discipline, if I go and say that this particular accident
has happened, then the first question that will come to you will be as to why were you there in
the scene site, what did you do, what happened, why did you go there and who were all there
with you and so on.
So, just for the fear of disciplinary action, and fear of all these red tapes, so the workers will
never report any accident, so that is a major cause for not reporting an accident. Then concern
about company's record, so too many accidents reporting may also spoil a company's record.
That is also an other reason why the accidents will not be reported in promptly. The next is
concern for company’s reputation.So, equal to record the company's reputation also maybe little in danger, so that is also one of the
concerns for workers not reporting accidents. Then fear of medical treatment desire to keep
personal record clear, if the same organization has other safety programs like incentives and so
on, rewards and all for very safe behavior in the construction site. So, just because of reporting
an accident may actually will not keep a personal record clear.
And that is also one of the reason why workers they are very hesitant in reporting accidents.
Avoidance of red tapes again and fear of discipline I said they are like together, so just because I
am reporting an accident, I maybe called for every investigation and every interrogation. So,
some workers they want to avoid and be quiet, so they do not report accidents. Then desire to
prevent work interruptions, suppose I just go and complain on something every time I maybe
called for interrogations and investigation.
So, there will be work interruptions at each and every point of time, this disturbance may also
keep the worker from high productivity. And poor understanding of importance of reporting
accidents, that is a main reason why workers do not report accidents. So, first step is to avoid and
clear all these barriers and the workers should be encouraged to report accidents. Some
suggestions are also given like for example, do not grill the worker or stressed the worker he
wants to report for an accident, try to take it up in a positive way and react the situation in a more
positive way and you should be appreciating for reporting on time.
So, that future major disastrous events will not have occurred. Make sure every worker knows
what kind of accidents should be reported, and what is the importance of reporting accidents in
time. And give more attention to prevention and control of accidents rather than blaming
someone or try to find faults with someone. Recognize individual performance on reporting all
these accidents, and demonstrate the belief by action. Suppose some accidents are reported
earlier, if too much of accusations and so on has happened to the worker who reported an
Then obviously workers will not come forward, and one execution has to happen in the sense
worker should be appreciated for reporting an incident. And some corrective actions were all done seeing these workers will generally get motivated to report accidents in future. So,
investigation do's and do not that we will see.
(Refer Slide Time: 17:48)
So, accidents should be investigated as soon as possible after they happen, because the more time
the team takes to start the questioning session and the witnesses involved, any witnesses who
were involved, what happens is? In the meantime, the workers may try to chat with each other
and the one worker’s perception may modify an other worker’s perception. And the total the
original scene of the entire accident scene may go lost.
And you will not be getting an accurate story of what happened. So, the workers who were
working close to the accident site may have a different picture and workers who are watching the
site may have a totally a different picture. So, if you want to get the real picture and understand
the root cause analysis, you should be starting the investigation as quickly as possible. And the
injured person’s version of an accident should be obtained as soon as his practical work and
other distractions start minimizing his memory.
And he gets distracted and totally he lost a scene of what happened. So, what happens is, it is
generally a human psychology that as time goes, any workers, any human being starts adding up
their own imagination also into the scene picture. So, if you want to avoid that and get a proper scene picture, then any accident investigation should start immediately. There are some
occasions wherein you should not quickly start the investigation.
For example, do not question a person just because your interrogation is taking time, is medical
treatment is getting delayed then do not even go near the investigation process. Suppose if this
investigation is making the worker very upset and he is in totally in pain, and you keep on
interrogating him under various situations, then better not to investigate the accident
immediately, you can do after he recovers partially, and then you can start doing investigations.
There are various investigative procedures that one should be followed during an investigation.
The investigator should have a familiarity on the equipment, operation, process involved. So,
first of all you should have a thorough knowledge on the total construction work, so that you will
be able to identify the faults and mishaps very quickly. The scope of investigation and size of the
team also should be determined based on the nature of the accident, magnitude.
For an very minor case, you may not have bring a big team, but based on the severity of the
accident and it is impact, yes you should be able to bring a big team for investigation. To obtain
the accurate facts, the investigator must should start on to the scene as quickly as possible and
start his investigation. And whenever any accident is investigated, multiple perceptions of the
investigation should be really looked at and multiple causation models also has to be really
And the real purpose of accident investigation is should be only to identify facts and to have a
corrective action rather than a cornering a worker or giving more emphasis and putting on
somebody into blame, so that should not be the main motivation. So, what should you do with
the actual investigation process?
(Refer Slide Time: 21:24)So, you should always first think of how should the level of investigation go? Should you have
intermediate levels or maybe first level will be only to analyze and understand what happened?
Intermediate levels will give you clues and hints, and if you are not able to put all the jigsaw
puzzles into one nice story. Then you may have to do 2 or 3 successive rounds in order to have a
very accurate picture of what happened, so that you should understand.
And also the time taken for the investigation also depends on the seriousness of the accident and
the effect of the accident on the project team. The next is thing is decide who will investigate,
because investigator should be able to continue with further investigation. Although he meets a
dead end, sometimes he starts with a question with a predetermined mindset, he goes starts
asking the questions.
And after some time, the witnesses you do not have anything else to continue and so on, then you
are actually in a dead end. So, you should always have an investigator who actually know tries to
put in dynamic situation and starts interrogating in a different, different scenario and different
perspective. And you should also decide how much time will be allotted, generally fixed time is
If you say within two days the investigation has to be completely done, then you are not going to
analyze a real reason for an accident at all. And for major catastrophes to happen, so has happened, the investigation shall start only after the first day treatment and so on. So, time
depends on amount of data collected, sometimes if there is too much of confusion and totally a
different, different picture from the witnesses.
And there are so many people involved in the investigation team and so with the as a witness,
then you have to have some more time get taken up for the investigation. Sometimes some the
cases can be so complicated that you may also have to do some measurements, experiments and
so on, then accordingly you can take more time for the investigation. But just because to close
the case, you should not be winding up the investigation, identifying someone and finish up the
You should be feeling totally confident that you have analyzed all the root causes of the accident
causation. So, and also you should also understand whether additional sources are required, for
example consultants, maybe even the team itself. Do you want subject matter experts, do you
want doctors, lawyers and so on that you should first of all decide and then start up your
The next thing is special equipments just for to test something external testing, are you want a
specialized computer software to analyze some material and debris and so on. Then accordingly
you should also plan for additional resources that are required in the investigation. So, now why
do you need special experts?
(Refer Slide Time: 24:27)Sometimes there may be an in-house accident investigation team to carry out the investigation
process. But sometimes the case is, accident is too complicated or it attract the media attention
and so on, then obviously you may have to bring in. Or sometimes if the particular accident
needs specialized experts and specialized equipment, as mentioned in the previous slide,
obviously you need to have special troop and also specialized equipments and software for the
Which may include employees with knowledge of the work, supervisors in the area of the work,
then health safety personnels it maybe from the same company or maybe if you want you can
bring some other external experts. Then employers with the experience in investigation and
representative from local government or police are also required if there is a serious danger and
the investigation required.
(Refer Slide Time: 25:27)How are the facts collected? What are the different forms of collecting evidences from the
construction sites, accident? Number 1, physical evidence, , physical evidences irrespective of
the people in the site. You can take photographs, videos, draw, measure, take physical
measurements, whatever you want, that is primarily call physical evidence. The next is witness
accounts, so who were all in the close vicinity of the accident.
So, those people's narrative experience on what happened in the accident that will form the
second level of data collection. And the third is you can also start prompting questions and
asking interviews through discussions and interrogations with various people involved who that
in the accident scene. And accordingly you may have interviewing sessions you may get some
And you can also have open ended questions to trigger out to have and more idea on other
directions and perspectives which you have not foreseen earlier. Physical evidence, for example
position on the injured worker, position of the faulty equipment, device, safety devices used,
position of the control operators, then the damage to equipment, housekeeping area, weather
conditions, lighting levels, then noise levels and time of the day at which accident happened.
And you can also take photographs along with written notes before anything is mood, disturbed
or modified in the place. And you can also have sketches of the scene based on measurements which can help in later analysis. And if there is any broken equipment debris or any samples of
materials involved, that can also be collected for later investigations and testings, test purposes.
Witness accounts, now witnesses can be all those people who were there.
And you should also see too that you are not interviewing the witnesses in as a group, you should
be trying to call them one after the other. Because as I told you earlier itself, the imagination or
the perception of one worker may always disturb the perception of an other worker. And if you
want to have a correct picture of the complete accident, you should be interviewing the witnesses
individually and not in groups.
And the witnesses have the opportunity to discuss the event among themselves, then individual
perceptions may go lost. And sometimes the witnesses maybe under severe emotional stress or
they maybe also completely scared of talking what happened and so on. So, it is better to
encourage them and talk to them, so that let them start opening their mouth and start talking
about the accident.
The next interviewing, so do's, some of the do's, you should also be putting the workers in a
proper comfortable mode, so that they will start speaking and explaining what happened and so
on. And if you want to have a statement correct and so on, so better not to corner the worker and
try to have a positive side of asking questions. And do not interrupt the when any worker or any
the construction personnel are speaking.
And do not prompt for hints and so on, let them speak continuously, so that the multiple
perceptions are generally got revealed. And also one other technique is always try to keep open
ended questions. So, that when these open ended questions are triggered, will does not have an
yes or no answer, then your third perception or a different perception of the entire picture will be
(Refer Slide Time: 29:16)So, investigation process, so the investigator should have maintained a notebook or should be
filing up all the scenes completely. So, at the accident scene, so is first to gather all information,
so notes on the basic source of written information. And it aids in the investigation process
interviews, follow up investigations and so on. If the picture is not clear, then they can actually
go back and forth on to the investigation page.
So, all these records should be maintained as a notebook or should be saved in a particular file
and as a folder. And the notebook should also have important contact numbers to contact people
who want to have more information and more data. And also basic essentials should be like who
was involved, who saw the accident first, who reported the accident and who was interviewed
and so on, what happened in the scene site?
And what do witnesses know, what evidence was obtained? What action was taken? And what
agencies were all notified? What time did the accident occur? And what time did you arrive? So,
primarily from the time at which the accident happened and the time you came to the spot for
investigation, all should be considered. Where did the accident occur? Then where were the
victims? And where were the witnesses? And where was the individual suspected of causing the
accident? All these should be investigated.When was the victim last seen, when was the suspect last seen? So, all these also should be taken
into account. Why did the accident occur, why was this accident reported, all has to be there, with whom was the victim seen and who are the weaknesses connected, how much damage has been done and what is the property lost and so on. So, complete interrogations have to be done
and you should have an answer for maybe multiple answers for each and every point.