A bicyclist died after being struck by a vehicle on Tucson’s far east side Sunday evening.

Pima County Sheriff’s deputies responded to reports of a cyclist hit by a vehicle at Old Spanish Trail and Rocking K Ranch Loop at about 5:50 p.m., according to a news release from PCSD.

Upon arrival, they found the cyclist, 35-year-old Benjamin Bruns with life-threatening injuries. He died at the scene, the news release said.

An initial investigation revealed Bruns was riding his bicycle along Old Spanish Trail when he was struck by a passing vehicle whose driver may have fallen asleep, the news release said.

Excessive speed nor impairment appear to be a factor at this time, the news release said.

The investigation is ongoing.