(Reuters) – Two Virginia state policemen were killed on Saturday when a helicopter in which they were riding crashed after assisting in efforts to quell clashes between white supremacists and counter-protesters in Charlottesville.

The pair were among three people who authorities said died in connection with the violence near the main campus of the University of Virginia. A 32-year-old women died when a car plowed into a crowd dispersing after police broke up the melee in the city’s downtown.

The helicopter pilot, Lieutenant H. Jay Cullen, 48, of Midlothian, Virginia, and Trooper-Pilot Berke M.M. Bates, 40, of Quinton, Virginia, died at the scene of the crash in Albemarle County, the state police said in a statement included in a Twitter message sent by NBC29 of Charlottesville.

No one on the ground was injured, it said.

President Donald Trump sent his condolences to the families of the officers and their colleagues in the Virginia State Police.

“You’re all among the best this nation produces,” Trump said in a Twitter message.

The Bell 407 helicopter went down 7 miles (11 km) southwest of Charlottesville, Jim Peters, a spokesman for the Federal Aviation Administration, said in an email.

National Transportation Safety Board spokesman Peter Knudson said the cause of the crash had not been determined. The NTSB is sending investigators to the scene, he said.