MASON CITY (AP) — A nurse, a paramedic and a pilot died when a medical helicopter crashed and burst into flames in a field in northern Iowa.

No patient was on board the helicopter from Mercy Medical Center-North Iowa when it slammed into the ground just north of Ventura in Cerro Gordo County around 9 p.m. Wednesday.

Butch Kozisek told the Mason City Globe Gazette that he had been startled by the sound of the helicopter flying so low and that he saw “one heck of an explosion” from his home less than a mile from the snowy crash site.