John Clayton Timbers, a well-known Tucson cyclist, was struck and killed by a vehicle while riding on Tucson’s east side early Tuesday morning.

Tucson Police responded to a report that a vehicle had struck a cyclist in the 5600 block of East Grant Road, east of North Craycroft Road, just before 5 a.m.

Upon arrival, they found Timbers, who was pronounced dead at the scene, according to Tucson Police.

Detectives were able to determine that Timbers, 78, was riding his bicycle westbound in the curb lane on Grant Road when he was struck from behind. The vehicle continued without stopping, according to TPD. Detectives believe the vehicle that struck Timbers was a red 2000s Nissan Frontier or Xterra, according to Tucson Police.

Timbers founded La Vuelta de Bisbee, a popular Southern Arizona stage race, in 1976. He won several high-profile races in his day, including the Manhattan Beach Grand Prix and the Iron Horse Classic in Durango, according to the Arizona Bicycle Racing Association Facebook page.

“John taught me many things about bike racing, and a lot about being a good human,” fellow cyclist and friend Alan Fischer posted on his Facebook page.