Each year, NFPA collects data on all the firefighter fatalities in the US
that resulted from injuries or illnesses that occurred while the victims
were on-duty. The term on duty refers to:
Being at the scene of an alarm, whether it is a fire or non-fire
incident (including EMS calls).
Responding to or returning from an alarm.
Participating in other fire department duties, such as training,
maintenance, public education, inspection, investigation, court
testimony, or fundraising.
Being on call or standby for assignment at a location other than at
the firefighter’s home or place of business.
On-duty fatalities include any injury sustained in the line of duty that
proves fatal, any illness that was incurred as a result of actions while
on duty that proves fatal, and fatal mishaps involving nonemergency
occupational hazards that occur while on duty.