JACKSON (WNE) — Two people were killed and five others are fighting for their lives after a head-on collision Tuesday afternoon in Grand Teton National Park.

Police said Craig Edward Aubuchon, 65, was driving a minivan southbound on Highway 89 Tuesday afternoon when he veered into oncoming traffic.

“For reasons unknown he drifted into the northbound lane and a Nissan Xterra collided with it head-on, center to center,” Wyoming Highway Patrol Lt. Matt Brackin said.

Aubuchon, of Town and Country, Missouri, was killed in the crash. His four passengers, two of whom were children, were rushed to St. John’s Medical Center.

One of the adults in the van sustained life-threatening injuries, Brackin said.

The driver of the SUV, Carol Lynn Roemer, was also killed. The Riverton resident was 68 years old. Her passenger sustained life-threatening injuries and is being treated at St. John’s Medical Center.

The wreck happened around 2:15 p.m. Tuesday, about half a mile north of the Jackson Hole Airport junction.

Grand Teton National Park rangers and Teton County sheriff’s deputies directed traffic around the accident via the Antelope Flats and Gros Ventre roads during the four-hour closure.

The National Park Service and Wyoming Highway Patrol are investigating the cause of the accident.

Police don’t believe drugs or alcohol were a contributing factor but autopsies will be done to rule it out, Brackin said.