Mr. Hinds, 51, was found unresponsive late Wednesday after an S.U.V. appeared to slam into the motorcycle he was riding near downtown Atlanta, the authorities said.

Brent Hinds, the co-founder of Grammy Award-winning heavy metal band Mastodon, has died after being injured in a motorcycle accident in Atlanta. He was reportedly 51.

"We are in a state of unfathomable sadness and grief," Hinds' former bandmates wrote in an emotional tribute to the late heavy metal rocker.