Four Categories of Event Analysis
Events can happen at any time, in any location, and to anyone.
All events at an accident scene can be categorized into one of four analysis categories. Your analysis of the event will vary depending on its category.
Significant events leading to an accident can happen anytime, ranging from a few minutes to weeks or even months prior. When identifying events, don't concern yourself with the sequence of events leading to the accident at this stage. It's not relevant at this point. What matters is identifying the actor and action that define an event.
Below are four analysis categories of events:
Actual Events: These are events that you can confirm actually occurred, meaning they were witnessed by one or more persons (preferably two or more) who can verify that it did happen. It is advisable to interview all witnesses to the event.
Bob and Bobbie saw Bill turn off the chipper power switch and then walk over and reach into the chipper in an attempt to remove some jammed wood.
Assumed Events: These are events that are presumed to have occurred but have not yet been verified. It's important to flag these somehow as a reminder that further investigation is required. Assumed events can be more challenging to confirm.
In any step-by-step process, you cannot proceed to step 3 without first completing the first two steps. If a worker is injured at step 3, you may assume they accomplished steps 1 and 2 unless it is established that they bypassed the first two steps. If completing steps 1 and 2 could have prevented an injury at step 3, and the worker is injured, you may assume the worker did not follow steps 1 or 2.
If Bill's hand was crushed while clearing a piece of wood that was stuck in a large chipper, we may assume he did not perform lockout/tagout, or we may assume that he performed lockout/tagout incorrectly. Only further investigation and analysis will uncover what happened.
Non-Events: If an event was supposed to happen, but did not, that is a non-event. Although non-events describe an event that did not occur, they should be captured because they may help discover conditions and behaviors relevant to the investigation.
Example: Bill did not try to start the chipper to verify lockout/tagout was successfully performed. He failed to perform the verification step of the lockout/tagout procedure.
Simultaneous Events: In some accident scenarios two or more events occur at precisely the same time resulting in a hazardous condition or set of unsafe behaviors that cause an injury.
Ralph wondered why the chipper was off and turned it back on at the same instant in time that Robert reached into the chipper to remove the jammed wood.
Knowledge Check Choose the best answer for the question.
5-2. Which category of events have happened but have not yet been verified?
You forgot to answer the question!