The incident occurred on Terminal Island below the Vincent Thomas Bridge at about 10 a.m.
Authorities said no one was injured. One person was evaluated by paramedics.
According to the fire department, there was a fire following the explosion that involved one big rig with an enclosed trailer that was knocked down.
The explosion was so powerful, it shattered windows at an apartment complex roughly two football fields away, fire officials said.
Residents in the area reported hearing the explosion and seeing a tall column of black smoke.
Police said an industrial accident was the cause of the explosion, nothing nefarious as the cargo container with the cars was heading out of the port, not in.
“We do have the bomb squad, we do have the hazmat team behind us, and we are hopefully going to be able to determine what caused this explosion shortly,” said Capt. Daniel Cobos of L.A. Port police.
The port was working under normal conditions.
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