Four people on a Southwest Airlines flight were taken to a hospital Friday after the plane encountered turbulence, according to Salt Lake City airport spokeswoman Nancy Volmer.

She said she didn’t know whether they were admitted to the hospital. Volmer also said she hasn’t heard about turbulence impacting other flights.

A Southwest spokesperson said Southwest Flight 1753, which flew out of Chicago Midway airport, experienced moderate turbulence on approach to Salt Lake City.

“Our initial reports indicate that, following an uneventful landing of the aircraft, three flight attendants and one customer were treated for minor injuries,” she said.

She didn’t say how they were injured, but said the seatbelt sign was on when the plane encountered the turbulence.