KING

A United Airlines 737 returns to Sea-Tac Airport after a row of seats slipped in flight, causing it to crash into another row of passengers on Sunday, August 3, 2008.

SEATTLE – A flight from Sea-Tac Airport to San Francisco had to turn around after a row of seats slid, crushing another row of passengers Sunday night.

United Airlines Flight 1139 took off at about 7 p.m.

A Sea-Tac Airport spokesman says while the plane was in the air, row number three slid back onto those passengers sitting in the next row.

However, a passenger on that flight tells KING 5 news the seats actually slid as the plane was just beginning to accelerate.

"The screaming was horrible," said the passenger, who added that four or five people got off the plane with police and paramedics after the flight returned to Sea-Tac. Airport officials say one passenger sitting in the fourth row was taken off the plane to Highline Community Hospital.

KING

A passenger took this photo of what appears to be a mechanic securing the seats that slipped on United Flight 1139.

United says a bolt appeared to be loose, causing the seats to slide. The passenger says mechanics came on board to tighten the bolts and take photos of the seats.

Passengers were given several options for gifts from the airline for the inconvenience, including bonus miles and travel credits.

Flight 1139 resumed to San Francisco at about 9:30 p.m.

The plane was a Boeing 737.