The people who work along one of Oakland's busiest thoroughfares looked at the cascade of water from a broken pump line yesterday in disbelief, as Centre Avenue disappeared under the brown surge 1 to 2 feet high.

"It sounded like lava swooshing by, and then I got up to look, and it was like a dam broke," said Erkan Taha, owner of the Dollar Plus store, who was wearing sandals after his socks were soaked at the busy intersection of Centre and North Craig Street. About a foot of water was in the store's basement.

The Dollar Plus and other businesses along Centre Avenue lost an afternoon of customers, as a stretch from Bigelow Boulevard to North Neville Street was shut down, but the effects of the unwanted water release spread far wider.

Thousands of households and other businesses in Oakland and the Hill District lost water service. Outages occurred both in surrounding blocks and miles away in Squirrel Hill, Shadyside, Point Breeze, Greenfield and Polish Hill, with no announcement by last night of when it would be restored.

The Pittsburgh Water and Sewer Authority last night issued a boil water advisory to residents who lost water service or who had low water pressure. Residents were advised that once water service was restored, they should boil water for one minute before drinking it.

The underground rupture occurred beside the Herron Hill Pump Station on Centre at North Dithridge Street. The nondescript red brick building that's generally ignored by passers-by but houses one of the five major pumping stations used by the Pittsburgh Water and Sewer Authority became the center of attention yesterday.

An array of lines goes underneath the area, with water from the authority's treatment plant in Highland Park pumped up to the Herron Hill reservoir, which then distributes it through a network running to neighborhoods.

Around 12:30 p.m., the underground leak caused a broad section of Dithridge to buckle, earthquake-style, and a torrent of water poured through the gaping crack onto a steep section of Centre and ran downhill several blocks to Neville.

Crews using heavy equipment had difficulty finding the precise location of the leak, which occurred amid a network of lines under Dithridge Street. As the afternoon wore on, water continued streaming out onto part of the street, though no longer resembling the whitewater rapids that had gushed over curbs earlier.

Many streets that had been closed around 12:30 p.m. were reopened by 4:30, though cars still had to plow through inches of running water and pedestrians had to jump small rivers along Centre.

People along the avenue stopped everything in early afternoon to watch and take photos of the rapids, which led to some basement flooding but no reported injuries.

"It was amazing. I'm from Texas, and we'd evaporate as a state if we lost this much water," said Sheila Smith, administrative coordinator for UCP Community Service Center at Neville. Center program participants with disabilities rely largely on ACCESS vans for transportation, which endured detours and delays most of the afternoon.

Crews finally pinpointed the source of the leak last night, among the six lines that run beneath Dithridge Street. Holly Wojcik, spokeswoman for the water authority, could not say when service would return to normal. Nor could she estimate the numbers of customers affected.

But isolating the source of the leak enabled crews to begin restoring pressure in other lines, she said.

Authority Executive Director Greg Tutsock said millions of gallons were lost.

Repair work could disrupt traffic around the intersection of Dithridge and Centre indefinitely, depending on what's required, he noted.

Water service returned sporadically for some customers as crews shut numerous valves trying to isolate the problem, but the authority issued a statement urging customers in the affected East End neighborhoods to conserve water.

Interestingly, some businesses a block or two from the line break had water service afterward, while others miles away in the Squirrel Hill business district had no or low water pressure.

Numerous high-rise apartment buildings in the vicinity saw their water pressure drop or disappear. Like others, the office of the 172-apartment Webster Hall in Oakland was besieged with questions from residents about the nature and duration of the problem.

"We're just telling them to hang in there," an office representative said.

UPMC hospitals and the University of Pittsburgh reported no initial problems, but some other schools -- including Allderdice High School in Squirrel Hill and Linden Academy in Point Breeze -- lost water, said Pittsburgh Public Schools spokeswoman Ebony Pugh.

Allderdice already was near dismissal time, so its school day was unaffected. Classes continued at Linden, where water was brought to the school for drinking and to drain toilets.

The break also affected transportation at Schenley High School, forcing students using Port Authority buses to go to another stop.

Assistant Fire Chief Jim Crawford said damage to businesses seemed surprisingly minimal, but there was flooding of apartment building basements.

The break was on the same block of Dithridge where a similar gusher occurred in August 2000. Local residents and business people said another smaller break occurred two years ago.

Bottled water for drinking and non-drinkable water for household use was available in Squirrel Hill at Maxon Towers, 6315 Forbes Ave.; UPMC Heritage Shadyside, 5701 Phillips Ave.; Weinberg Terrace, 5757 Bartlett St.; The Commons, 2025 Wightman St.; and, drinking water only, at Engine Co. 18, 5858 Northumberland St.

Other sites to obtain water were in the 4400 block of Centre Avenue, Oakland; and at Milliones Manor, 2827 Bedford Ave., Hill District.