A storm system spawned tornadoes as it swept across the upper Midwest and into Pennsylvania, killing at least one person, flooding basements and leaving tens of thousands of homes and businesses without power overnight and into Friday.
In western Pennsylvania, Allegheny County and Pittsburgh officials declared a state of emergency as residents dealt with flooding and damage from the torrential downpours.
The worst damage in Ohio was across the north-central part of the state, where the National Weather Service confirmed a tornado in Shelby Thursday afternoon and were investigating tornado reports in Medina, Stark and Summit counties, said meteorologist Walter Fitzgerald.
The storms tore the roof off a high school, damaged several other buildings, and downed trees across a swath of the state.
In Marion, Ohio, about 40 miles north of Columbus, a falling tree limb struck a sport utility vehicle, killing the 22-year-old driver a few blocks from her home, police said.
'A lot of cleaning'
Some 18,000 Marion utility customers still didn't have power back Friday morning. "About half the city is without power, and we have a lot of cleaning up to do in the next few days," said Marion police Lt. Michael Shade.
Power lines were down in Shelby, and the tornado tossed cars around and blew out vehicle windows.
In nearby Ashland County, the roof of a high school gym in Sullivan was blown off, according to sheriff's Capt. Terry Hamilton. Classrooms and a ballfield were also destroyed.
"We've got trees down every place," Hamilton added.
Officials later confirmed that the damage was caused by a tornado.
Wind also damaged a restaurant and blew out car windows in a supermarket parking lot in Salem, about 15 miles southwest of Youngstown.
Outages, flooding in Penn.
In Western Pennsylvania, emergency dispatchers said they received several reports of funnel clouds, and about 35,000 homes and businesses were without electricity Friday morning. Duquesne Light spokesman Joe Vallarian said some customers might not have service until Saturday, because of heavy damage to power lines.
Windows at Pittsburgh's Carnegie Science Center were shattered when the storm hit the building, with 800 to 1,000 people inside. One girl there was treated for a cut on her hand. Several other buildings were damaged and trees were uprooted. In all, about two dozen people in the city were treated for minor injuries, authorities said.
The town of Millvale, on the outskirts of Pittsburgh, was hit hard by flooding: 25 of about 200 flooded homes had water up to the first floor, county Executive Dan Onorato said. Eighty families had to be evacuated and 45 businesses also flooded.
The same town had been badly damaged when the remnants of Hurricane Ivan caused a creek to overflow in 2004.
Some 250 other properties were affected by flood waters across Allegheny County.
Hundreds of passengers at Philadelphia International Airport were stuck on planes that sat on runways for hours Thursday. US Airways said it canceled 530 flights across the country Thursday, 133 of them out of Philadelphia.
The airline said bad weather elsewhere created a backlog of planes waiting to takeoff, stranding some passengers on the tarmac for up to six hours. Nearly 30 planes were lined up at one point Thursday.