The cars were swept back by the flood and by 1:30 a.m. on Sunday the garage structure gave way.
Shocked residents woke up and were trying to comprehend the damage.
"Any cars that were left in the garage were destroyed," said Bob Feldman. "No one has gone down there yet, so we haven't seen the actual damage but it's pretty ugly."
Despite the extensive damage no one was hurt.
An evacuation center has been set up for residents displaced by the flood.
The American Red Cross center is set up at Robert Milikan Middle School. The school is located on Sunnyslope Avenue in Sherman Oaks.
Less than a dozen people have made use of the center.