Authorities say a medical helicopter responding to the scene of a fatal accident in southwestern Ohio crashed when it apparently hit some power lines.

It was not immediately clear how many people were aboard the helicopter when it went down early Tuesday or if any them were injured.

The helicopter was responding to a two-vehicle accident that occurred around 4:15 a.m. in Milford Township.

The helicopter crash occurred a short time later.

Authorities say one person was killed in the vehicle crash and three others were injured.

The cause of that accident remains under investigation.