OMAHA, Neb. (AP) — A worker at a Tyson Foods building in Omaha was injured in an early-morning accident.

Omaha television station WOWT reports that the man was taken to the hospital after getting his hand caught in a chain at the plant around 2:45 a.m. It took crews about half an hour to extricate him.

Authorities say the man was at the CHI Health Creighton University Medical Center with critical injuries. It’s not yet clear what caused the accident.