Some passengers were terrified, convinced the plane was going down. One seasoned traveler said it was the roughest flight he’d ever taken. A woman on board felt like she was experiencing an earthquake.

Serious turbulence on a Delta Airlines flight headed to Europe sent 25 people to hospitals and forced the plane into an emergency landing in Minneapolis, the airline said. Some aboard the flight from Salt Lake City to Amsterdam weren’t wearing seat belts and were thrown about the cabin, one passenger said.

Twenty-five passengers were hospitalized after a Delta Air Lines flight encountered “significant turbulence” on Wednesday. The flight, DL56, was headed from Salt Lake City to Amsterdam but had to be diverted to Minneapolis-St. Paul, according to a statement from Delta.