The rupture occurred on the 1200 block of North Formosa Avenue at about 1:30 p.m.
Water flooded from Lexington Avenue to Santa Monica Boulevard. In total, five apartment buildings and five commercial buildings were affected by the water.
Formosa was closed between Fountain Ave. to Santa Monica Blvd.
Los Angeles Department of Water and Power personnel arrived on scene. Water service in the area was shut off while the problem was addressed. At 9:30 p.m. about 60 customers remained without water.
The L.A. Fire Dept. requested temporary shelter for residents until the extent of damage was determined.
The cause of the break was not immediately known. The water main is reportedly more than 70 years old.
DWP officials said water service should be restored by 1 a.m.
Formosa is expected to remain closed from Fountain to Santa Monica until Friday.