The National Fire Protection Association has collected information on on-duty firefighter fatalities since 1977 and published annual reports on key findings. Historically, the on-duty criterion meant that deaths were included when they were due to 1) traumatic injury or 2) sudden cardiac incidents, strokes, aneurysms, or medical conditions while the victim was on duty. Fatalities due to heart attack, stroke, aneurysm, or other medical conditions when firefighters were off duty were not included in the study except in cases where the victims made a specific medical complaint while on duty.

Read the full report from the NFPA by clicking the link.