ERIN, Wis. (AP) —  Authorities in Wisconsin say the pilot of a small advertising blimp was seriously burned when the aircraft crashed at the U.S. Open golf tournament, on Thursday.

The man was the only person aboard when the craft went down shortly before midday at the Erin Hills golf course in Erin, Wisconsin. The blimp went down in an open field near the course.

A statement from the Washington County Sheriff’s Office says the pilot suffered serious burns and injuries. He was taken to the hospital by air.

The statement says the blimp was on fire or smoking and went down rapidly. The Sheriff’s Office asked the Federal Aviation Administration and National Transportation Safety Board to help investigate the cause.

A woman who witnessed the crash  says she saw flames as the aircraft deflated and floated to the ground.

Mary Ruediger was visiting her parents who live near Erin Hills golf course when the blimp went down nearby Thursday. Ruediger says she saw the blimp disappear behind the tree line, drove to another vantage point and saw black smoke along with three fireballs erupting after it hit the field. The 45-year-old Ruediger says first responders were quickly on the scene.