An explosion at a hash oil factory in Los Angeles injured 11 firefighters while they were caught in a ball of fire trying to extinguish the blaze.
The Los Angeles Fire Department says "one significant explosion" shook the downtown area at 6:30pm on Saturday (local time). Firefighters had to run through flames that were nine metres high and wide, fire department captain Erik Scott says.
The 11 injured firefighters suffered burns ranging from minor to serious. Three are in a critical condition and two are on ventilators, according to the Associated Press. All are expected to survive.
Firefighters were called to the area after receiving a report for a fire at a one-floor commercial building. There was initially light to moderate smoke when firefighters entered the building and went onto the roof, but then the explosion occurred.
Scott says those who were on the roof scrambled down a ladder that was engulfed in flames.
Over 200 firefighters were called to the scene and dozens of fire trucks reportedly blocked the street. The fire also spread to other buildings, but this was quickly extinguished.
The fire occurred at a smoking accessories and supplies store called SmokeTokes, which Scott says is a maker of "butane honey oil". Butane is a gas that ignites easily and is used as part of the process to extract THC from cannabis to create hash oil. The oil is then used in vapes, edibles and other products.
