MECHANICSBURG, Pa. (AP) — Two upstate New York men aboard a helicopter were killed when the aircraft crashed in a Pennsylvania backyard, authorities said.

No one on the ground was injured in the Thursday night crash, Cumberland County spokesman John Bruetsch told news outlets.

The helicopter's pilot, Mark D. Croce, 58, and a passenger, Michael Capriotto, 63, both of Orchard Park, were killed, the county coroner's office said. The helicopter was headed at the time from Washington, D.C., to Buffalo, New York.

Pictures and video of the crash site from news outlets show a residential neighborhood that's part of Silver Spring Township, near Mechanicsburg. The helicopter crashed behind a residence where people were home at the time, Bruetsch said, and there was a large debris field. But the home wasn't damaged.

The helicopter wasn't medical, Bruetsch said, but no further details regarding its provenance were immediately available.

The cause of the crash wasn't immediately clear. The Federal Aviation Administration and the National Transportation Safety Board were to investigate, Bruetsch said.

Bruetsch said the investigation would be a “long, drawn-out process.”