Last Updated Aug 31, 2016 12:27 PM EDT
LONDON -- A United Airlines flight bound for London made an emergency landing at Shannon Airport in Ireland on Wednesday after severe turbulence that left 12 passengers needing hospital treatment, officials said.
All but one of the injured had been discharged from University Hospital Limerick after receiving treatment for minor injuries, officials said. One patient was still being assessed.
United Airlines Flight 880 originated in Houston and was supposed to land at London’s Heathrow Airport.
United said that “severe and unexpected turbulence” caused the diversion of the Boeing 767-300 plane, which was carrying 207 passengers, three cockpit crew members and 10 flight attendants.
Passenger Nikki Hartin Boriack told CBS News that most of the passengers were asleep when the turbulence hit about three hours into the flight.
“It happened very suddenly,” Boriack said, describing the turbulence as a “big drop” followed by the plane bumping and then another drop.
Some passengers who weren’t wearing seatbelts hit their heads as they were thrown out of their seats, Boriack said.
One flight attendant hit their head badly and was bleeding, Boriack said. The flight attendant later told Boriack that they hadn’t experienced such turbulence in 20 years.
The flight landed at Shannon Airport about three hours after hitting the turbulence.
Airport officials initially said 16 people needed hospital care, but later indicated only 12 had been treated after the incident. Others received treatment for lesser injuries at the airport.
The patients were treated for soft tissue injuries, cuts and minor head injuries, according to a hospital statement. United Airlines said one of its flight attendants was still being treated at the hospital.
The airline said 10 passengers and two flight attendants needed hospital care.