The break occurred around 2 a.m. in the 500 block of S. Serrano Avenue. Water was seen rushing out of the broken line and into the garage, sending residents scrambling to get their cars out.
The Los Angeles Department of Water and Power said the broken pipe belongs to personal property, so the city is not responsible for the repairs.
Firefighters arrived on scene to pump out the water from the garage. Cleanup was underway.