Results of an autopsy have determined that the driver of a Volvo involved in a three-person fatality in May died of natural causes. The collision, which killed everyone involved, shook the Wood River Valley community, taking the life a recent graduate of the local fire academy and a retired couple that had been active in nonprofits in the valley.

According to the Blaine County Coroner’s Office, Peter Jarvis, 82, of Sun Valley, the driver of the black 2010 Volvo that crashed head-on with a 2007 white Toyota pickup truck driven by Piper Reed, 34, of Ketchum, died naturally, with no indication of a heart attack, stroke or brain aneurism. In addition, no alcohol or drugs were found in his system.

The accident occurred on May 29 just before 10 a.m. on state Highway 75 south of the Elkhorn Road intersection. According to the Blaine County Sheriff’s Office, Jarvis was traveling south on the highway when his car left his lane, “crossed over the center lane divider, and entered into the northbound lane of traffic,” hitting Reed’s truck that was traveling north.

Jarvis was pronounced dead at the scene, and his passenger and wife, Sally Jarvis, 82, later died at St. Luke’s Wood River Medical Center. Reed also died at the hospital following injuries sustained from the crash. Reed’s golden retriever, Remy, was also killed in the collision. According to the Sheriff’s Office, all occupants were wearing seatbelts at the time of the crash.

At the time of the accident, the Sheriff’s Office said the crash was under investigation. The Sheriff’s Office confirmed Wednesday that the investigation has since been closed, and no determination was found as to why Jarvis left his lane and collided with Reed.