A burning truck's fuel tank exploded on Thursday while Los Angeles firefighters were trying to battle the blaze, injuring seven of them, including two critically, authorities said.
The explosion of one of the truck's natural gas tanks occurred shortly before 7 a.m. in the Wilmington neighborhood, fire department spokesman Nicholas Prange said in an interview.
Six firefighters were taken to a hospital, he said. In TV news helicopter video, discarded firefighting gear could be seen at the site where the injured crew members were initially treated.
The vehicle was the tractor portion of a big rig and was fueled by compressed natural gas carried in two 100-gallon tanks, one of which exploded, said Capt. Erik Scott, also a department spokesman.
"That explosion was significant," he said. "The ball of flame was as high as these telephone poles, and it actually did explode one of the transformers nearby."
The truck was completely destroyed, and firefighters stayed well back as a small flame continued to burn in the mangled wreckage, the helicopter footage showed. Scott said the second fuel tank was "still off-gassing and therefore there's a minor threat."
The truck driver's status remained unknown, and other key details of the incident had yet to be learned, Scott said.
"The surrounding circumstances that led up to this tragic incident are still too new," he said.
The blast occurred adjacent to an industrial area separated from a neighborhood by a wide street and a rail line.
Wilmington is 18 miles south of downtown, near the ports of Los Angeles and Long Beach.
