Darrell Sapp, Post-Gazette Water rushes down a staircase just off Fort Duquesne Boulevard during a water main break today. Click photo for larger image. Related articles 6 bus routes detoured by water break Water shortage changes Downtown's routine

A gusher from a ruptured water main that flooded Downtown Pittsburgh's Gateway Center was reduced to a comparative trickle by late this afternoon.

Mayor Tom Murphy announced that all but a couple of the 13 valves on and connected to the 36-inch, cast-iron pipe had been shut off. Crews were trying to reroute service to buildings that lost water or experienced low pressure since the break occurred beneath Fort Duquesne Boulevard at 10:35 a.m.

The break forced police to barricade streets around Gateway Center in Downtown Pittsburgh, and one building was evacuated. Residents of the Gateway Towers condominiums were asked late this afternoon to find other accommodations for the night.

City Public Works Director Guy Costa said the basements and first floors of 10 buildings were flooded. Numerous others in Downtown were reporting low water pressure.

Costa asked drivers to stay away from Fort Duquesne Boulevard, Commonwealth Place, Stanwix Street, Fifth Avenue, Liberty Avenue and Sixth Street in the area.

But officials said rush-hour traffic could use Penn Avenue, which has reopened, and the 10th Street Bypass.

The break occurred on Fort Duquesne Boulevard next to KDKA-TV's studios in One Gateway Center. Stanwix Street was shut between Fort Duquesne and Penn Avenue and water had flooded the post office at 625 Stanwix.

At 12:15 p.m., police gave the orders for the evacuation of Fifth Avenue Place and Highmark offices in the old Joseph Horne & Co. building -- now called Penn Avenue Place -- at Penn and Stanwix.

Highmark has a combined 4,000 workers in the Penn Avenue Place building and its headquarters across the street at Fifth Avenue Place.

Although officials asked that no other buildings be evacuated, some schools and businesses closed and people headed home early because their buildings lacked working restrooms.

Sidewalks were crowded with gawkers and, in one case, a woman who worked at the Allegheny County Housing Authority at 625 Stanwix who was told to leave. "They sent us home because we couldn't flush the toilets,'' she said, refusing to give her name.

Point Park University closed, as did Community College of Allegheny County, both on the North Side and its center in 625 Stanwix.

Gateway Center subway station, one of the lowest points in the lower Golden Triangle and in proximity to the flooding, remained open and operating normally.

Large sump pumps next to the track "loop" in the station are able to handle significant volumes of water that can enter the system from rain and normal leakage.

Nevertheless, the Port Authority had to reroute buses past closed streets, delaying mid-day service and sending riders scurrying to find their buses.

The break created a fourth river -- more than 2 feet deep -- near the Hilton hotel and Gateway Towers and continuing up past KDKA-TV. KDKA's vehicles parked in the basement were swamped by water washing down a ramp. Five trucks that provide remote broadcasts were damaged. The graphics department may have lost computers, and station officials were worried about cameras stored in the basement.

KDKA was considering setting up a remote broadcast location if electricity is cut off.

Although water flooded numerous underground vaults that contain heavy-duty electrical equipment for Downtown buildings, Duquesne Light Co. reported no problems as of 12:30 p.m. Gateway Towers condominiums asked for their power to be shut off because electrical controls in the basement were flooded.

"If the power is off at any building, it was a decision of building management to shut it off," spokesman Joe Balaban said. "Vaults are built to withstand a certain amount of water for a certain length of time. We have two Downtown supervisors standing side-by-side with the fire department as a precaution. If we're asked to cut power, we'll abide."

Mayor Murphy said employees of Gateway Center buildings should monitor news sources throughout this evening to determine whether they should report to work tomorrow.

Basement flooding was reported throughout Gateway Center, including in underground parking garages. Officials said a plan would be devised to allow vehicles to be recovered from the garages. Commuters who park there should consider alternate transportation or other parking areas tomorrow.

Costa said there were reports of gasoline mixing with water, possibly because of flooded gasoline tanks.

But Allegheny County Health Department Director Dr. Bruce Dixon said there is litle concern about bacterial contamination from the water because it is treated drinking water, not sewage. The line is the main water supply for Downtown and runs directly from city reservoirs in Highland Park. Officials don't expect a water supply problem for the city despite the massive loss.

The break also affected pressure on the North Side.

Spokeswoman Linda Ross said that Mercy Hospital's North Shore Campus experienced a temporary dip in water pressure. It is now back or near normal.

"They put the hospitals back online first," Ross said. "It's a very minimal concern for us. Patient care was not disrupted."

The main hospital, Uptown, was not affected by the water main break, she added.

The water main break affected pressure at Allegheny General Hospital on the North Side, where officials began diverting ambulances around 11:45 a.m., said spokesman Dan Laurent. The hospital has since regained pressure and is again accepting emergency patients.

The break was affecting water service as far away as Grant Street.

The Allegheny County Courthouse, William Penn Hotel and the Allegheny Building lost water service.

Kaufmann's on Smithfield Street had low pressure.

More details in tomorrow's Pittsburgh Post-Gazette.