Two big car pileups in Box Elder County shut down I-15 for hours and prompt highway patrol troopers to issue a warning to drivers.
Heavy fog and snow were major factors to the pileups that happened around 2:15 p.m. The storm was so intense a medical helicopter couldn't land and a critical patient had to be taken to the McKay-Dee Hospital via ambulance. Five people also suffered minor injuries.
A section of I-15, near Willard Bay, was closed for about two and a half hours while troopers sorted through 31 accidents.
Utah Highway Patrol Lt. Lee Perry said, "We had a few crashed southbound. People started watching northbound, [and the] next thing you know people are hitting their brakes northbound."
Utah Highway Patrol Trooper Todd Johnson said there were 20 vehicles involved on the southbound side and 11 vehicles on the northbound side.
Steve Wilson was one of those drivers involved in the pileup. He said, "The fog moved in, snow came, and somebody started spinning, and it was just a chain reaction."
Wilson and his 3-year-old grandson were headed to Davis County when he saw brake lights in front of him. It was too late. He said, "I slammed on my brakes and went into a car."
They watched as medical crews took four people away, including a woman in critical condition. He said, "There was one that had to be extricated from a small car. She was in really bad shape."
A Brigham City police officer's car was among those hit. He was not in it at the time and is OK.
The scene had law enforcement making a plea to drivers. "People, slow down so you'll all get where you need to go and have a Merry Christmas instead of having something bad happen to you," Perry said.
Law enforcement took photos and measurements at the scene to help recreate the accidents later. That's when they'll decide what citations, if any, should be issued.
The pile up is one of just many accidents in the last 24-hours. The Utah Highway Patrol assisted more than 35 accidents in Utah County last night.
Salt Lake County was even worse. Troopers there responded to more than 120 accidents.