Benjamin Cox, Utah Highway Patrol
A car that slid into westbound traffic on U.S. 6 Wednesday was struck by a truck.

SPANISH FORK — Drifting snow was blamed for an accident in which a woman was killed and three other people were injured Wednesday.

The crash happened about 6:20 p.m. on U.S. 6 in Spanish Fork Canyon. The Utah Highway Patrol said drifting snow blew into the path of a car being driven by Brian Hughes, 41, of North Salt Lake. Hughes lost control and slid into westbound traffic, troopers said.

The car was then T-boned by a truck pulling a trailer, said UHP trooper Cameron Roden.

Kristen Hughes, 18, died at the scene of the crash. Brian Hughes and another of his daughters, Michela, 12, remain hospitalized in critical but stable condition. Troopers said Nathan Slade, 27, of Murray, was seriously injured in the truck crash. His brother, Shaun, 22, escaped injury.

Traffic was shut down for hours while several emergency helicopters responded to the crash. An ambulance hit a medical helicopter, making it unable to take off.

"The ambulance got too close to the chopper and ended up clipping the rotor," Roden said. "We called in a third helicopter."

Troopers didn't issue citations at the scene but are investigating speed as a possible factor in the crash.

"We encourage people to slow down anytime there's a possibility of black ice," Roden said. "There's definitely a possibility of black ice and drifting snow in that canyon."