SAN PEDRO, Calif. (KABC) -- A semi-truck carrying six large lithium-ion batteries overturned Thursday in San Pedro, sparking a fire and hazardous materials concerns while also forcing a closure of the 47 Freeway and the Vincent Thomas Bridge, causing major traffic backups in the area.
The crash was reported shortly before noon in the 900 block of North Seaside Avenue, according to the Los Angeles Fire Department.
A hazardous materials team was sent to the scene, and fire crews assumed a defensive posture against the flames, fire officials said. After about 12 hours, the fire was still burning.
A 300-foot perimeter was established as hazardous smoke and flames shot up in the air earlier. Fire crews said attempting to put the fire out with water is not safe.
"Lithium-ion batteries take copious amounts of water, so it's generally better to just let them burn," explained LAFD Capt. Adam Van Gergen. "It's also better for the environment. We're concerned about water runoff getting into the drains, eventually getting into the ocean, it could create an environmental disaster."
There were no immediate reports of injuries, evacuations or widespread hazardous warnings.
The cause of the crash remains under investigation.
Joshua Acosta used a tow truck company's drone camera to capture the moment the truck exploded.
"It could have gone a thousand different ways. I'm glad it went this way and no one was injured," he said. "Even the driver of the big rig that flipped, he's fine."
WATCH: Video shows moment semi-truck carrying lithium-ion batteries explodes
The 47 Freeway was closed between Harbor Boulevard in San Pedro on the west side of the Vincent Thomas Bridge and the 710 Freeway to the east. The closure prompted a major backup of traffic -- largely truck traffic -- in the area.
California Highway Patrol officials indicated that the Vincent Thomas Bridge could potentially remain closed for as long as 24 to 48 hours.
The Pacific Maritime Association released a statement about the crash, saying it has disrupted operations at the Ports of Los Angeles and Long Beach and has changed its dispatch plan "significantly."
"Our organization is taking direction from the Los Angeles Fire Department which has created a 1,000-foot radius zone from the fire in order to protect public safety," read the statement.
PMA said the following terminals will have all labor orders cancelled for Thursday night and Friday:
Los Angeles Mayor Karen Bass released a statement Thursday, saying her office has been in touch with port officials and Caltrans.
"I have been briefed on the San Pedro Bay Port Complex fire by LAFD Chief Kristin Crowley, and I want to thank our LAFD firefighters for keeping drivers, Port workers and the surrounding community safe as this situation is resolved," she said. "LAFD firefighters arrived on scene shortly after reports of the traffic accident and established an isolation perimeter. Hazardous material specialists are also on scene. My office has been in touch with Port of Los Angeles leadership and Caltrans officials regarding the impact of the closure on Port functions as well as traffic detours. We are working quickly to resolve this issue. Safety, as always, is our top priority."
A similar incident happened in July in which a truck carrying lithium-ion batteries also overturned and caught fire, shutting down the 15 Freeway between Los Angeles and Las Vegas for 48 hours.
Firefighters expect Thursday's fire could also take that long to extinguish.
"Right now, we are doing monitoring, but we are not anticipating any danger to the public with this," said Van Gergen.
City News Service, Inc. contributed to this report.