"Then you realized it was an earthquake, because the whole building was shaking," said Jessie Jones, 19, at the store in Sharon, about 60 miles northwest of Pittsburgh. "It was like you lose your equilibrium, like your knees buckled."
The Friday afternoon earthquake was centered about 15 miles northeast of Sharon, near the Ohio border, according to the U.S. Geological Survey in Golden, Colo. The quake hit at 3:52 p.m. and had a magnitude of 5.2.
The quake lasted less than a minute, and there were no immediate reports of injuries or significant structural damage.
"I thought the whole house was going to fall down. It shook that hard. I thought it was a tornado," said Patty Cook, 28, of Jamestown, a small town near the quake's epicenter.
The quake was felt in Cleveland, Columbus, Detroit and the Buffalo, N.Y., area but was still relatively minor, said John Minsch, geophysicist for the Geological Survey.
"It was moderate, probably enough to knock things off of shelves, but we wouldn't expect extensive damage," Minsch said.
Magnitude 5 can produce moderate damage.
But the Earth rarely trembles in this part of the country, so the event shook some people up.
The new Vocal Group Hall of Fame and Museum, which honors groups such as the Vogues and the Four Freshmen, rattled and rolled in downtown Sharon.
"It was like a tumbling noise, like a herd of buffalo coming through," said Anthony Watkins, a 22-year-old supervisor who watched the plate-glass windows wobble at the 4-month-old museum.
It was strong enough to shake bricks loose on a chimney and knock 1,200 baseball cards and jars off the shelves at the Britton family's house in Jamestown. David Britton was having a happy-hour beer with co-workers at a bar in nearby Greenville at the time and rushed home.
"The bartender thought someone hit the building with a car," Britton said. "But we walked outside and saw it was more than just one building. Everybody was out in the street."
"It was like riding on a bumpy road," said Steve Fought, a campaign spokesman for U.S. Senate candidate Mary Boyle, who felt the tremor at his office in downtown Cleveland.
The earthquake shook the fifth floor of Hamot Medical Center in Erie. Workers there reported that it felt like heavy equipment was trying to move the building.
Emergency dispatchers were swamped with calls -- and most of them were from people who just wanted to know what had happened, said Lester Pfaff, an information services systems manager at the Crawford County Office of Emergency Services. He reported 151 calls in a half hour.
"We didn't have any real major damage that was reported. Just a very few minor things: windows broken and people saying it knocked some things off the wall," Pfaff said.
Marko Bourne, a spokesman for the Pennsylvania Emergency Management Agency, said people in all the western counties except Washington and Greene -- in the far southwestern corner of the state -- may have felt the earthquake.
The earthquake center in Colorado will determine during the next few days on which fault the quake occurred, said Waverly Person, a geophysicist at the center.
The quake could be felt as far away as Ontario, on the north shore of Lake Erie, but was missed in parts of southwestern Pennsylvania -- such as Pittsburgh -- that are closer to Sharon.
"We've had this kind of thing happen before. It's not uncommon. Some people will feel something and others not," Person said.
The last time an earthquake was reported in Pennsylvania was February 1996 in Berks County. The 2.3-magnitude tremor rattled residents. The county was hit by 4.6- and 4.0-magnitude quakes on Jan. 15, 1994.
The clerks at Reyers shrugged off the event. They remembered at least two other small quakes in the past 20 years.
Cashier Belinda Goodman, 25, joked that Sharon could handle the tremors even if "California has got a monopoly on it."