Last Updated Feb 26, 2020 7:17 PM EST
Carson, California — Investigators are looking into what sparked a tremendous explosion and fire at the largest fuel refinery on the West Coast. The blast there was felt miles away and a huge ball of fire could be seen at the center of the facility.
"There were several explosions, up to potentially three explosions, that preceded the fire itself," according to LA County Fire Department inspector Sean Ferguson.
The boom could be heard at least 25 miles away.
One of the busiest freeways in the nation — the 405 — shutdown overnight when more than three dozen LA County firefighters raced to extinguish the blaze.
It happened at the Marathon Petroleum Refinery, south of LA. What burned was not crude oil.
Fire officials told CBS News the incident was a massive propane explosion.
The cause still under investigation and the bulk of the refinery, back up and running.
This refinery produces more than 360,000 barrels of oil a day and there are no signs that will be impacted. Fire officials told CBS News there were no injuries, and there does not appear to be a threat to the public. They continue to monitor air quality, making sure there are no toxic hazards to surrounding neighborhoods.