The 10 Freeway was shut down Sunday morning after a fire broke out among a large stack of pallets sitting below a freeway off-ramp in downtown Los Angeles.

The fire was first reported around 7:30 a.m. at an off-ramp on the Santa Monica Freeway near Lawrence Street off-ramp.

According to the Los Angeles Fire Department, heavy smoke forced the California Highway Patrol to close the freeway in both directions until it was safe to reopen. The Fire Department said the thick black smoke was causing a “zero-visibility environment.”

The fire was burning in a massive stack of wooden pallets that were stacked from the ground all the way up to the freeway itself. Fire officials said there was a “significant” amount of fuel to burn.

Drivers were encouraged to take alternate routes or avoid traveling in the area altogether.

By 8:50 a.m., the fire was knocked down and the freeway was reopened, according to CHP.

In total, 86 firefighters were assigned to the incident with crews accessing the fire from both sides of the freeway. They used forklifts at the scene to move pallets around so crews could access the interior of the fire.

Commercial buildings were threatened by the fire, officials said, but no structures were immediately exposed.

No injuries were reported. The cause of the fire is under investigation and LAFD Arson investigators responded to the scene.