Authorities say four people were injured in an explosion south of downtown Los Angeles.
L.A. City Fire Spokesman Matt Spence says unknown glass cylinders exploded at about 6:30 p.m. in the rear of a building at 2528 South Grand Avenue. Paramedics took four patients – two male, two female – to area hospitals. Two were listed in fair condition, two in critical.
The blast took place a few blocks from the University of Southern California campus near Interstate 110.
Spence says it is not clear what exploded, or exactly where the blast occurred in the building, but no fire broke out and there were no further explosions.
A joint investigation involving the city's arson counterterrorism unit, L.A.P.D. and the L.A. County Hazmat team is currently underway.