It happened on Springfield Road between Broadway and Berkeley.
Aqua repair crews were on the scene trying to excavate a 12-inch cast iron main that ruptured after 2:00 p.m.
Viewer video obtained by Action News showed gallons and gallons of water gushing up from below the street in front of Penny's Restaurant.
Witnesses described a dramatic scene after the main broke.
"Water was gushing up where the curb is, then the street rose, and there was a crack in the street. A trash truck came by and drove into the hole, busted it up, drove out of the hole. That's when the cops pulled up, and they took over," said John Kelly.
"All that water got on the grass, all over the sidewalk. I had to walk up on the grass to get to my place. It looked like a stream going down. Flooded with water," said Orlando Vargas.
The break has disrupted water service in the area. There was no immediate word how many customers were affected.
Repair work was expected to take 8-12 hours.