Los Angeles County fire officials said fireworks were found all around a mattress warehouse that went up in flames Saturday night.
But they don't know if the rockets were to blame for the two-alarm fire at the Florence business, NBCLosAngeles.com reports.
The fire was reported around 10 p.m. and within an hour, the flames spread to a second building.
The blaze, which left one firefighter with minor injuries, was placed under control at 2 a.m.
Los Angeles County fire investigators have been on the scene all morning trying to determine the cause of the blaze.
