Electrical panel explosion claims the life of a career assistant fire chief, an electrician, and seriously injures an assistant building engineer - Illinois.
On June 11, 1999, a call came into central dispatch at 1300 hours reporting smoke coming from the electrical closet on the second floor of a large department store. The fire department dispatched two engines, one ladder truck, one ambulance, and one battalion chief. After checking the store, the Chief was informed there was no fire; however, the store lighting was not operable, therefore, all customers were evacuated from the store, and the responding companies were released to return to the station. The Chief requested that the departmentís Fire Prevention Bureau respond to further evaluate the situation at the store. The chief engineer of the department store had called an electrician to evaluate the electrical problem and to determine why the emergency generators were not operating. The electrician, an Assistant Chief with the Fire Prevention Bureau, and the Assistant Building Engineer of the store proceeded to the engineering room on the first floor to check out the electrical problem. The electrician began by trouble-shooting the emergency power system which controls the emergency generator and transfers the emergency lighting circuit from the utility to the emergency generator. After testing the transfer panel, he moved to the emergency breaker compartment (480 volts, 200 amps), removed the cover panel, and proceeded to test the circuits. Initial testing showed power on all terminals. When the electrician started to test the circuits again, a fault occurred, resulting in the formation of a fireball seriously injuring the assistant building engineer and fatally injuring the Assistant Chief and electrician. NIOSH investigators concluded that to minimize the risk of similar occurrences, employers should: 1. develop and implement a hazardous energy control program which includes procedures to de-energize, lockout, and tagout any electrical component/system that has a fault or potential fault prior to initiating work; 2. train workers in the basic concepts of hazardous energy control; 3. ensure that workers wear the appropriate personal protective equipment when working on energized parts, including voltage testing; and, 4. conduct a flash hazard analysis to determine the flash-protection boundary.