Jason Donahue, left, of Clairton and Dustin Tichenor of Bethel Park push their vehicle to safety after it was stranded in rising water on Route 51 near Bausman Street.
Saw Mill Run (Route 51) flooded near the Liberty Tunnel.
John Heller / Post-Gazette
Pittsburgh Mayor Luke Ravenstahl checks on the cleanup operations in Hays.
Jon Schmitz/ Post-Gazette
Flooding at the intersection of Rt. 88 (Library Road) and McNeilly Road.
Several vehicles were stranded.
Flooding on at the intersection of Rt. 88 (Library Road) and McNeilly Rd. stranded cars this afternoon.
Kevin Quigley, assistant director of Pittsburgh's Department of Public Works directs the clean-up at the intersection of Routes 51 and 88 where Saw Mill Run flooded this afternoon.
Pittsburgh firefighters lead a stranded passenger to safety after her vehicle was stuck in rising water on Route 51 near Bausman Street.
John Heller / Post-Gazette
Flooding at Ramp and Baldwin streets in Hays left behind gravel and mud on the roadway.
John Heller / Post-Gazette
Pittsburgh paramedic Don Cunningham checks out the water level of the Streets Run Creek from Ramp Street in Hays.
By Jon Schmitz, Mackenzie Carpenter, Joe Smydo, Liz Navratil, Marcus Schwarz Pittsburgh Post-Gazette
Pittsburgh emergency personnel responded to flash flooding in the South Hills this afternoon after a thunderstorm dropped large amounts of rain all over the region, closing roads and trapping drivers.
No major injuries have been reported.
Routes 51 and 88 were closed to traffic for several hours in the area around the busy intersection after water flooded the roadway and then left behind mud and other debris. The roads did not reeopen until shortly after 7 p.m.
An emergency dispatch supervisor said four swift-water rafts -- three from Allegheny County and one from city -- were dispatched to help deal with the flooding.
There also were multiple reports of water on roadways in the southern part of the county.
In Findlay, the National Weather Service reported about 4:45 p.m. that water from a creek has run out of its banks and is flooding bridges and homes near McClaren Road. Earlier, water flooded the intersection of Cliff Mine and Mahoney roads. Cliff mine is now open, but police have blocked off Mahoney in that area.
A Pittsburgh firefighter working with rescue teams along Route 51 near the insection with Route 88 said there were many people standing on the roofs of their cars during the height of the flooding. They were rescued by public safety workers.
A Pittsburgh fire battalion chief was injured during rescue efforts, he said.
Curtis Ross, of Uniontown, who works for Inland Water Pollution Control, said he was part of a crew the company had working in the creek that runs along Route 88 on a sewer bypass pipe.
He said the water in the creek went from being a foot deep to 15 feet deep in a span of 20 to 30 minutes. His father-in-law, also working there, told him it was coming in two-foot waves.
"He said it looked like the ocean," he said.
The workers evacuated the area and went down Route 88 toward where their cars were parked. Mr. Ross said his 2010 Chevy Cobalt had water nearly up to the window and hood.
"It's ruined. It's done," he said.
He said the force of the water severely bent a large section of sewer pipe that's in the creek near McNeilly.
He also said water was rushing about eight inches above the small bridge on McNeilly near Route 88. He said he didn't see anybody trapped and no one had driven into the water in that area.
The rushing water was strong enough to push a Dumpster from a Monro Muffler shop all the way across Route 88.
McNeilly was left covered with debris, including construction barrels.
Matt Phillips, who works at Warp Speed Motor Sports, an auto shop near the intersection of Routes 51 and 88, said 12 cars at the shop were flooded. He said some of them were expensive vehicles such as Porsches and it is likely eight of them would not be repairable.
"This is phenomenal. I just kind of dumbfounded right now," Mr. Phillips said as he was looking over the parking lot with the damaged vehicles.
He said the creek regularly floods, but this is the worst he has seen. At its peak, he said, the water was almost three feet high on the building of the shop, which is across the road from the creek and set back from the roadway.
"Something needed to be done a long time ago," he said.
By 2:30 p.m., emergency workers were reporting that water around the intersection of routes 51 and 88 was receding but that another storm cell was expected to move through.
City officials said those were the only areas they were aware of with active flooding. The emergency gates to keep drivers out of a flood-prone area of Washington Boulevard during high water have not been activated.
Traffic in flooded areas is very congested.
Route 51 is at a standstill from the area of flooding to the Liberty Tunnel. West Liberty Avenue is backed up from Dormont to the tunnel.
The National Weather Service issued a flash flood watch for Allegheny, Washington, Westmoreland and Fayette counties until 5 p.m.
Parts of Allegheny, Washington, Westmoreland, Indiana and Fayette counties are under a weather service flood watch, less urgent than a warning, until 8 p.m.
Rain fell at the rate of 2.5 inches an hour in areas south of the Pittsburgh International Airport. Castle Shannon reported that it received 1.7 inches an hour.
Ruth Nolla, head cashier at the Red, White & Blue Thrift Store on Saw Mill Run Boulevard, said firefighters have shut down the road right outside the shop.
"It's completely flooded," she said, noting that she could leave the store if she wanted to travel through the Liberty Tunnel but would not be able to drive in the opposite direction.
Dozens of vehicles have tried to pass through the water, she said. Many of the trucks succeeded, but most of the cars got trapped when the water rose to cover large portions of their tires, she said.