Tragedy hit the annual Tour de Tucson on Saturday when a driver collided with on of the fields. The incident happened around three hours into a race that was sixty competitors strong. The impact took down 10 riders and sent 5 of them to the hospital with injuries.

Witnesses say it happened when an elderly driver turned into the oncoming field of cyclists. Apparently the man got out of his car, looked at the the injured cyclists and promptly drove away.

Of the five riders taken to the hospital Saturday, Gary Stuebe, 42, from Surprise, Arizona was the only rider that sustained life-threatening injuries. Stuebe was taken from a Tucson to St. Joseph Hospital in Phoenix, and was listed in critical condition as of Monday night.

Pima County Sheriff’s deputies continue to follow leads in their search for the driver, and are asking anyone with photos of the accident to call police. The sheriff’s office sent out 70 letters to local residents over the weekend to aid in their search.