The fire spread nearly a full city block.
It took firefighters an hour to get the blaze under control. At one point, fire crews had to evacuate when electrical wires fell inside the burning building.
Several city trucks and forklifts inside the facility were destroyed in fire.
There were no reports of injuries, and it is unclear what sparked the fire.
At least three fire departments -- South Pasadena, Pasadena and Alhambra -- responded to the three-alarm blaze.
The Associated Press contributed to this story.
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