Shortly before 11:38 a.m. on January 2, 1984, the primary electrical power system failed at The Westin Hotel, and security personnel were immediately dispatched to the electrical equipment vaults located in a sub-basement to investigate. In rapid succession to the power failure and before the security personnel were able to reach the electrical equipment vaults, a fire alarm signal was received from a smoke detector in the switch gear room. The responding security personnel encountered "heavy smoke", and a series of explosions occurred in the switch gear room. The evacuation alarm system then sounded throughout the hotel, and the Boston Fire Department was automatically notified.
Fire department investigators were unable to firmly establish the cause of the short circuit in the electrical switch gear; however, investigators believe that moisture from an unidentified source caused the short circuit. The short circuit of the high voltage switch gear eliminated the supply of power to the hotel's primary electrical systems and damaged the emergency electrical system conduit. This caused the loss of lighting on the corridors and in the enclosed stairways in the 38-story high-rise tower and the loss power to the hotel's smoke control system. Emergency power to the telephone and fire detection and alarm systems was supplied by batteries, allowing those systems to remain in operation.
The loss of the hotel's primary and emergency electrical power systems, combined with the accumulation of smoke in the basement garage areas where the stairways terminated, created a dark, smoke filled environment in these stairways (which occupants of the hotel were reluctant to enter) and then severely hampered occupants in their ability to quickly travel down the stairs and exit the hotel.
Occupant of the hotel were successfully evacuated during this incident. As a result of this successful evacuation, a human behavior study was performed in order to document how properly functioning automatic detection and alarm systems and a trained staff can contribute to the effective handling of an emergency situation.
For the full NFPA Fire Investigation report.