A series of explosions at a fireworks plant in Jennings, Oklahoma on June 25, 1985, killed 21 people and injured 5 others. This was the second-deadliest fireworks factory explosion in the U.S. reported to the NFPA between 1950 and 1986.
The incident was most likely the result of careless unloading of pyrotechnic materials from a pickup truck to an adjacent assembly building. It was only a matter of seconds from the initial ignition before the explosions leveled most of the facility. NFPA members can download the full investigation report for free.
NFPA 1124: Code for the Manufacture, Transportation, Storage, and Retail Sales of Fireworks and Pyrotechnic Articles provides the information and guidelines necessary to keep these types of events from happening in the future.