The fires all burned in the 100 block of McLellan Drive between 1 a.m. and 4 a.m.
Police and firefighters responded to the first fire at 1:08 a.m. on the second floor of a parking structure at a condominium complex. The fire was confined to one car, police officials said.
A second fire was then reported across the street, on the third floor of an adjacent parking structure.
At the same time, someone reported that a Dumpster was burning near a business blocks away, according to police.
Around 4:10 a.m., a fourth fire was reported on the third floor of the parking garage where the first fire occurred.
The San Mateo County bomb squad brought an arson dog to search both parking structures.
The South San Francisco Police Department and South San Francisco Fire Department are investigating the fires. Anyone with information is asked to call police at (650) 877-8900 or fire at (650) 829-6645.
