Water started gushing along Sunnyside between Tollhouse Road and Sierra Avenue early on Monday morning.
Right now, the road is free of any standing water, except in the yard of a home on Sunnyside.
There's a vacuum truck working on getting the water out.
Sunnyside is shut down due to the break just north of Tollhouse - and drivers are asked to avoid the area.
No word on when the street will reopen, or what caused the rupture.