Los Angeles city firefighters responded to reports of exploding ammunition at 10680 Elkwood Street around 11:18 a.m. The blaze was located just off the northern end of the main runway at Bob Hope Burbank Airport.
Traffic on the nearby 5 Freeway slowed as firefighters attempted to prevent the fire from spreading.
Massive flames and huge plumes of smoke shot out from the building. It took fire crews 36 minutes to get the blaze under control.
The 80-year-old owner was transported to a local hospital in serious condition. The extent of his injuries and his name has not been released.
The cause of the blaze was under investigation but officials said the building housed Hollywood Engineering which supplies ammunition for movie shoots.
CNS contributed to this report.