Sauk County dispatchers said a 64-year-old man fell out of a roller coaster at Mount Olympus in the Wisconsin Dells Thursday night.
Dispatchers said the man fell 15 to 20 feet and landed on the floor.
A Mount Olympus employee said the man fell off the Opa roller coaster at the theme park, which is in a building behind the water park. The theme park is closed, but the water park is still open.
Officials said the man was not moving but he was breathing when they took the 911 call around 5:35 p.m.
The man was transported to St. Clare's hospital in Baraboo, and was then transported by Med Flight to UW Hospital, authorities said.
Lake Delton police said this is not a criminal investigation, but the incident will be investigated by the Wisconsin Department of Occupational Safety and Health.
According to a release, Mount Olympus staff members have been very cooperative.