Early in the morning of October 26, 1997, an explosion occurred in a store in Mableton, Georgia. At the time of the incident, the store was occupied by only four employees, and not open to the general public. It is believed that a LP cylinder being stored in the loading dock developed a leak, and the cloud of propane gas was ignited either by a thermostat or an overhead heating unit. The initial explosion caused 150 feet of masonry block wall to collapse outward into a parking lot, and knocked over a storage trailer that was parked outside the building. During fire-fighting operations, personnel reported at least three explosions, likely BLEVEs of three other cylinders. It is also believed that the partition between the stockroom and sales floor was damaged at the ceiling level, allowing the products of combustion to spread horizontally through a void space above the sales floor.
Based on NFPA’s investigation , the following factors are considered to have contributed to the loss of property in this incident.
- Improper storage of LP cylinders within the occupancy (the cylinders were stored inside which was not in compliance with NFPA 58)
- Failure of one of the cylinders, which created the cloud of propane gas
- A closed water valve, which limited the available water supply to the sprinkler system and fire streams