The Incident
During a stretch of high summer temperatures in a mid-rise commercial office building, the HVAC system was struggling to keep upper floors comfortable. To pull cross-ventilation through the floor and ease foot traffic between departments, office staff routinely propped open the self-closing fire doors that separated each floor from the central stairwell. Wooden wedges, recycling bins, and a fire extinguisher were the usual props. Floor supervisors walked past the arrangement every day and said nothing.
The fire started on a lower floor when an overheated lighting ballast ignited paper stored beneath the fixture. The alarm sounded and the fire department was dispatched automatically. Smoke loaded with carbon monoxide and the combustion products of synthetic furnishings entered the stairwell through the propped lower-floor door, and the vertical shaft worked exactly the way a chimney works — drawing hot gas and smoke up through every other propped door on the way.
Workers on upper floors opened their suite doors to a stairwell already at zero visibility. One employee, attempting to reach a secondary exit through a smoke-filled corridor, became disoriented and was overcome. The outcome, per the FACE investigation: one office worker died of smoke inhalation in what fire engineers would otherwise classify as a survivable event.
Timeline
- Two weeks before — Stairwell fire doors on multiple floors are wedged open daily to fight summer heat and move people between departments. The practice is normalized; nobody reports it.
- Earlier that morning — Building maintenance logs a complaint about HVAC underperformance on the upper floors. No interim plan is issued. Doors stay wedged.
- Moment before — Smoke detector on the lower floor activates as the ballast ignites stacked paper files. The alarm sounds building-wide.
- Point of failure — Smoke enters the stairwell through the propped lower-floor door, climbs the shaft via stack effect, and rolls onto upper floors through every other propped door. The rated compartmentation that the building was designed around no longer exists.
- Response — Fire department arrives within minutes and locates one unresponsive occupant in an upper-floor corridor. The worker is pronounced dead at the hospital from smoke inhalation.
What Went Wrong (Root Causes)
Hazard
- Rated fire door assemblies were defeated by wedges and stored objects, eliminating the smoke barrier between occupied floors and the exit enclosure. Under 29 CFR 1910.37(a)(3), exit routes must be free and unobstructed, and exit doors must not be blocked or impaired.
Procedure
- No written procedure required daily walk-through verification that stairwell doors were closed and latched. No facility plan existed for summer HVAC shortfalls, so workers invented their own ventilation fix. NFPA 101 requires fire door assemblies to be self-closing and positively latching — that requirement was never operationalized on the floor.
Supervision
- Floor supervisors observed the propped doors every shift and did not act. No competent person was assigned to inspect egress components. There was no close-the-loop mechanism for a worker who did flag the HVAC problem.
Training
- Occupants did not understand that fire doors exist to stop smoke, not just flame, and that a single propped door on the fire floor is enough to contaminate the entire stairwell. Evacuation drills had never simulated a smoke-blocked primary stair.
What Would Have Stopped It
Apply the hierarchy of controls in order. Engineering is where this case is won: magnetic hold-open devices tied to the fire alarm system allow doors to stay open for daily traffic and release automatically the instant smoke is detected — satisfying both the comfort complaint and 29 CFR 1910.36 / NFPA 101. A maintained HVAC system removes the original motive to defeat the doors. Administrative controls — a written no-prop policy, daily egress inspections by a named competent person, and drills that simulate a blocked primary stair — backstop the engineering. PPE is not a factor here; you cannot respirator your way out of a compromised egress route.
The single highest-leverage action is the one that costs the least: walk the stairwell doors today and remove every wedge.
Action Steps For Your Site
- Walk every stairwell and corridor fire door on every floor today. Remove wedges, bins, and any object holding a rated door open. Confirm each door self-closes and latches from any position (29 CFR 1910.37; NFPA 101).
- Verify exit routes and stairwell landings are clear of stored materials, surplus furniture, holiday décor, and recycling — per 29 CFR 1910.37(a)(3).
- Confirm exit signs are illuminated and emergency lighting functions in every stairwell and windowless corridor (29 CFR 1910.37(b)).
- If doors are being propped because of a real HVAC or traffic-flow problem, escalate it in writing this week and propose magnetic hold-opens tied to the fire alarm as the engineered fix.
- Publish a stop-work and no-retaliation reminder: any worker can report a blocked exit, broken closer, or failed alarm component directly to facilities, and facilities will report back what was done. This is your close-the-loop.
Two-way discussion prompts for your huddle:
- Where on our floor would you prop a door if nobody was watching, and why? What is the underlying problem we should fix instead?
- If our main stairwell filled with smoke right now, what is your second route, and have you ever walked it?
Verification question: Pick one stairwell door on your floor. Is it closed and latched right now — yes or no? If no, who are you telling before lunch?
Comprehension check: In your own words, why does one propped fire door on the fire floor endanger people four floors above it? (Answer involves stack effect and loss of compartmentation — every occupant should be able to say this.)
Sources
- NIOSH FACE Report 99-F47 — Office Building Fire Fatality — cdc.gov
- OSHA 29 CFR 1910.37 — Maintenance, safeguards, and operational features for exit routes — osha.gov
- OSHA 29 CFR 1910.36 — Design and construction requirements for exit routes — osha.gov
- NFPA 101 Life Safety Code — Fire Door Assembly Requirements — nfpa.org