The collection of more than 5,000 pounds of illegal fireworks were seized in a pre-July 4 holiday sweep. The accident occurred as police bomb squad officers were in the process of confiscating the cache in a South Los Angeles neighbourhood, the LAPD said on Twitter.
“Some of the fireworks were being stored in our bomb squad trailer as a precautionary measure. Unknown at this time what caused the explosion,” the LAPD said on Twitter.
Los Angeles City News Service (CNS), ABC News and television station KCAL-TV reported that the blast was triggered when police attempted to safely detonate a portion of the explosives.
Video footage carried on KCAL-TV showed a bomb squad tractor-trailer truck blown apart in a fireball that overturned a nearby parked car and set off alarms in the neighbourhood.
The explosion also damaged a number of buildings and scattered debris on the streets, local media outlets reported.
The fire department said city building and safety inspectors were evaluating damaged homes to determine “if anyone will be displaced.”
Mayor Eric Garcetti said on Twitter that he was “closely monitoring” the situation and had directed the LAPD “to conduct a full investigation.”
The blast came four days before the July 4 Independence Day holiday.