MILFORD TOWNSHIP, Butler County (AP) — A medical helicopter responding to the scene of a fatal accident in southwestern Ohio crashed early Tuesday when it hit power lines, but no one aboard the aircraft was seriously injured, authorities said.

Three crew members were in the CareFlight helicopter, en route to a two-vehicle accident involving two pickup trucks that occurred around 4:15 a.m. in Milford Township, according to the Butler County Sheriff’s Office. The aircraft was approaching the scene when it crashed into the power lines and went down.

According to a statement issued by CareFlight, no patients were in the aircraft, which was being operated by Air Methods, and the crew members were able to safely exit the helicopter. The cause of the crash will be investigated by the National Transportation Safety Board and the Federal Aviation Administration.

Butler County Chief Deputy Anthony Dwyer told WXIX-TV that one crew member suffered “an unknown injury” and was taken to a hospital. The other two crew members were treated at the scene for minor injuries.

Authorities said one person was killed in the vehicle accident and three other people were injured. The cause of the accident remains under investigation.