The break was reported at 1:20 a.m. near Fountain Avenue between La Cienega Boulevard and Hacienda Place.
The roads were shut down and traffic was diverted as crews worked on repairs.
"This was a rapid water scene," Property Manager Jeff Daly said. "The firemen were very careful, even themselves, getting across it. So you weren't coming down here for anything."
The gushing water made quite a mess at one apartment complex, flooding the lobby and garage.
"I bolted out of bed, and I walked down and I see this," Chris Matsumoto said of the flooding. "I'm about to go and see my car in the basement and I'm afraid of what I'm going to find."
On Tuesday morning, muck and mud were scattered throughout the area and water was still sitting in the garage with several vehicles inside.
According to an update issued by the Los Angeles Department of Water and Power Tuesday morning, 10 residents were left without water.
Anyone with property damage can file a claim on the LADWP website.