Event Sequencing
In this step, the investigator must take the identified events and arrange them in the proper sequence to accurately determine how the initial event transformed a planned work process into an unintended accident.
You can arrange the events in a sequence moving forward through time from the initial event to the final injury event moving forward by asking "what happened next?" You can also use backward tracing which is valuable in sequencing because it's more likely contributing events will be identified while working backward through the sequence.
Ensure that you are constructing only one event. If an event is difficult to understand, it may be because the description is too vague or general. To solve this problem, increase the level of detail. Strategies to increase detail:
- Look around: Determine if anything else was said or done before or after the event you are currently assessing.
- Separate the actors: Remember, an actor may be a person or an object performing a specific action. If an event involves actions by more than one actor, break it down into two events. If the event contains the conjunction "and," it is likely a combination of two events. You can identify some combined events in the sample sequence of events in the next section.
Sample Sequence of Events
Below is an example of a sequence of events of an actual fatality investigation conducted by OSHA. It gives you a good idea what a sequence looks like.
Key: Actor, Action Conjunction
- At 12:30 PM Employee #1 returned to the worksite from lunch.
- At 12:35 PM Employee #1 started laying irrigation pipes into a 2-ft deep ditch.
- At approximately 12:40 PM employee #1 oriented an irrigation pipe vertically.
- The pole contacted a high voltage power line directly over the work area.
- Employee #2 heard a 'zap' and turned to see the mainline pipe and Employee #1 falling into an irrigation ditch.
- Employee #2 ran to Employee #1 and noticed that he appeared to be unconscious.
- Employee #2 pulled Employee #1 out of the irrigation ditch.
- Employee #2 ran about 600 ft to his truck.
- At 12: 45 PM Employee #2 placed a call for help on his mobile phone.
- Employee #2 ran back to Employee #1.
- At 12:55 PM paramedics arrived.
- At 12:57 PM paramedics started administering CPR on Employee #1 using a heart defibrillator.
- At approximately 1:10 PM the paramedics transported Employee #1 to the hospital.
- At 1:30 PM the attending physician pronounced Employee #1 deceased.
Knowledge Check Choose the best answer for the question.
5-4. If the event contains the conjunction, "_____," the event is likely to be a combination of two events.
You forgot to answer the question!