GREAT FALLS (AP) — A member of the Cascade County Search and Rescue team and his 10-year-old son were killed in a weekend crash that also injured his wife and critically injured their two other children, the sheriff's office said.

Tyler Weir, 35, and his family were returning to Great Falls to help with a rescue mission Saturday when the crash occurred, the search and rescue team said in a Facebook post.

Weir had pulled over to the side of the road between Great Falls and Belt and was attempting a U-turn when his SUV was broadsided by a semitrailer, the Montana Highway Patrol said.

The SUV went off the road and down an embankment.

Wyatt Weir also died in the crash. Jennifer Weir was hospitalized in Great Falls in serious condition, Sheriff Jesse Slaughter said.

The two other children, 6-year-old Wakely and 8-year-old Wes, were flown to Harborview Medical Center in Seattle, Slaughter said. They remained in intensive care on Monday, hospital spokesperson Susan Gregg told ABC Fox Montana.

Tyler Weir was a vice commander with the search and rescue team and a master sergeant with 13 years of experience with the Montana Air National Guard. Jennifer Weir is also a search and rescue team member and is a secretary for its board of directors.