At about 8:30 p.m., crews noticed water coming up from an area that had been backfilled and prepared for paving, according to LADWP officials.
"While compacting the concrete aggregate base in advance of final street resurfacing, water began to pool at the surface toward the eastern edge of the work area," LADWP said. "Crews are now excavating to find the source of the leak and assessing the extent of the damage to immediately begin additional repairs."
Possible leak could delay Sunset Boulevard reopening in West Hollywood
Before the latest development, the affected section of Sunset Boulevard was expected to reopen later this week. Officials have not said how the latest incident could affect that timeline.
LADWP crews have been working around the clock since the water main break that was reported last Thursday morning on Sunset Boulevard and Holloway Drive.
Roughly 17 million gallons of water poured out of the pipe and flowed down West Hollywood streets, pushing around cars and flooding garages while shifting massive chunks of asphalt and concrete slabs.
City News Service contributed to this report.