A truck full of lithium-ion batteries is burning in Los Angeles, shutting down ports and a bridge. It’s not clear what the batteries were for — but LA’s Vincent Thomas Bridge, leading to the Port of Los Angeles and next-door Port of Long Beach, has been shut down for at least 15 hours now while local firefighters let the truck burn. State Route 47 was also closed in both directions as of a couple of hours ago.

Amazingly, a local towing company caught the explosion on camera from a nearby drone:

Both the Port of Los Angeles and the Port of Long Beach have shut down a number of terminals while the fire continues to burn. As of 12:10PM PT on Friday, the truck was still on fire, and both the ports and bridge were still closed, Los Angeles Fire Department spokesperson Ren Medina told The Verge.

Firefighters are nearby and are actively monitoring the situation; as of 10PM PT on Thursday, the fire was expected to last “at least another 24-48 hours.”

As we’ve seen with several EV battery fires, big concentrated lithium battery fires can be very difficult to put out: firefighters sometimes douse them with thousands of gallons of water only to see the fire restart as additional battery cells heat up to the point they combust. Once a cell gets hot enough, it’s said to go into “thermal runaway,” at which point it can sometimes restart a fire. The LAFD confirms this is a case of thermal runaway.

EV packs are particularly dense with cells, but we don’t yet know if they were involved here — the LA Fire Department spokesperson says it’s not even clear who owns the truck, let alone what it was carrying yet. LAFD could only confirm they are lithium-ion batteries at this point.

Pepe’s Towing Service owner Josh Acosta, who filmed the explosion with his drone, didn’t immediately respond to a request for comment. But he’s apparently planning to publish more footage: “Full video on YouTube is going to be insane!!!” he wrote.

Umar Shakir contributed to this story.