MENDON, N.Y. (AP) — The remains of three National Guard members killed in a helicopter training accident were recovered and were being transported from the western New York crash site Thursday, escorted by police and fire vehicles.

The troops died when their UH-60 Black Hawk medical evacuation helicopter crashed in a farmer's field in rural Mendon, south of Rochester, around 6:30 p.m. Wednesday. There were no survivors.

First responders lined part of the route and saluted as a procession accompanying a medical examiner's vehicle drove to the Monroe County Medical Examiner’s Office in Brighton on Thursday morning.

The names of the soldiers have not been released.

The cause of the crash was under investigation. Witnesses who called 911 reported hearing the sounds of an engine sputtering and said the helicopter was flying very low, Monroe County Sheriff Todd Baxter said at a news conference Wednesday evening.

Photos from the scene showed the wreckage in flames on a snow-covered field.

The helicopter flew out of the Army Aviation Support Facility at Rochester International Airport, and was assigned to C Company of the 1st Battalion, 171st General Support Aviation Battalion, according to Eric Durr, the public affairs director of the New York State Division of Military and Naval Affairs.

The unit, with about 80 members, is a medical evacuation unit whose mission is to pick up casualties on the battlefield and transport them to military medical facilities, Durr said.

About half the unit spent most of 2019 deployed in Afghanistan.

New York Gov. Andrew Cuomo directed flags on state buildings be flown at half-staff on Thursday to pay tribute to the National Guard members.