Data Collection
Data is the backbone and lifeblood of any research or investigation. A case stands or falls, the guilty are punished and wrongs are righted, only with adequate quantities of right data. In accidents, data is the rare factor, because accidents happen without warning or control, and much data can get compromised or lost by essential accident response services and well - meaning and curiosity-seeking public - or by carelessness in the chain of custody.
1. In a Perfect World
You may be lucky. You may be in a country which has a full-time forensic team on standby to rush to an accident site right behind or along with the ambulance and the police when the first information reaches the authorities. And you are lucky enough to reach the site fast.
Then your job is easy. The paramedics have first shot at the site, trying to save dying victims and patch up the injured to transport them to ICUs and clinics. Police cordon off the area so nobody tramples on accidentally - or modifies intentionally - any of the evidence.
As part of the forensic team you have almost equal powers with the police to approve or deny others access to the site artefacts. Even the police are trained to respect your domain. They wear shoe covers and hand gloves and watch where they walk and what they touch. They sequester potential witnesses for your questioning as soon as they have elicited as much case evidence as they can from them.
You go in with your cameras and specimen kits, special lights and field test equipment, and record everything you are likely to need. Another member of your team handles the witnesses and debriefs them. Or vice versa.
Some specific individual or group is already in charge of the most important immediate tasks after an accident:
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Rescue operations;
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Medical treatment of the injured;
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Prevention of further injuries; and,
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Securing the site to protect the evidence from wilful or unwitting compromise.
You collect the following data, as appropriate:
- Long-term history:
- Original designs, subsequent modifications;
- Construction records, safe work procedures (SWPs);
- Material indents and deliveries, test records;
- Use histories, and maintenance and repair records;
- Risk assessment and management records; and,
- Personnel and organisations in various stages of construction and use.
It may fall to your lot, as a civil engineer, to stabilise the site against repetition of the mishap or further progressive collapse. If you see a beam precariously sagging, you would have to try to prop it up from further sagging - trying to push it up to its original position may neither be possible nor wise, because it may produce further damage.
Advanced countries have strict standard procedures for securing the site for the forensic team. Until this team releases the site, nobody can enter it without specific approval, and even then, only with proper accessories to prevent site contamination, and under strict supervision.
Without such control, forensic engineering would be quite difficult and unreliable.
2. Welcome to the Real World
More often than not, the accident is past history by the time you are in the loop.
Except in rare instances - admittedly increasing due to the ubiquitous CCTVs watching over almost every aspect of our lives - in most countries, the accident is long gone and the site cleaned up before any real investigation gets under way. This puts an extra burden on the forensic engineer, and he needs to have access to a variety of methods and techniques to seek out the truth from the available data after the event.
However, even though the clean-up is over by the time you are called in to investigate, generally it would be worth your while to visit the site to view the lay of the land, the ambient conditions, the scale of operations, etc. There could be exceptions.
In a case concerning a formwork collapse a few years ago, I was called in a few months after the accident, by which time the dead bodies had been removed and the blood had been hosed off, the collapsed formwork had been removed, replaced by a spanking clean and perfect replacement formwork, and the casting of the permanent structure already started.
While I was testifying as expert witness, the other side lawyer asked me if I had visited the accident site, I simply said "No.". When the lawyer wanted to make an issue of it, implying that I had failed in my duty as an investigator, I explained that a visit long after the clean-up would not have been fruitful, and that I had enough certified photographs, videos, and eye-witness accounts to extract all the information I wanted for my forensic analysis.
In most developing and under-developed countries when an accident happens, it is a free show for curiosity seekers (and let us admit it, even to most of us, intelligent, mature adults!) and chaos reigns immediately after the accident. It is a free-for-all, with anybody and everybody standing around busily watching the show, most chipping in with well-intentioned but unhelpful suggestions, and many actually entering the accident site and handling artefacts and people with avowed intention of saving persons in distress or articles liable to damage.
But unfortunately, they are also irrevocably destroying valuable evidence that would have helped find how the accident happened and possibly guide how to prevent future accidents.
Often, it is also the occasion for unscrupulous persons to steal things - even off of the dead and wounded - and for supervisors and managers to modify the scene to protect them from litigation. Even in the best of countries, watches, hand-phones and wallets vanish. It is not also unusual for an investigator to find that a safety harness has been placed next to or even on a dead fallen worker, or a brace in a scaffold which had not been in the photograph taken yesterday, to be suddenly in place today! In such situations forensic engineering is an academic topic for journal publications and conference presentations, but not useful for a practical investigation of the accident.
Also, forensic investigators are not too popular because they probe into tragedies, scratching emotional wounds, and asking inconvenient and embarrassing questions. Not having the authority of the police or the power of medical personnel, forensic investigators are often the last, unwelcome guests in the chain of command.
Still, you do the best you can, and collect whatever data you can in the best way possible. Do keep records of how, when and where you got the data, so that you will not be held responsible for ineffective investigation later on. Once you collect any data, authenticate it, because your word without corroboration will not be worth much in court as evidence.