Brent Hinds, former guitarist and vocalist with Grammy-winning heavy metal band Mastodon, died in a motorcycle crash in Atlanta late Wednesday night, police said, leaving bandmates in a state of "unfathomable sadness and grief." He was 51.

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.