A multiple-vehicle crash, involving three semi-trucks, injured five people early Friday, January 20, 2012. The automobile accident occurred at about 3:12 a.m. along I-84 in Box Elder County

That a semi-truck jackknifed during slick and snowy conditions, when the semi hit another tractor-trailer. The two wrecked semis were in or near the emergency lane when a third semi-truck jackknifed and slid into the first crash.

Responding emergency crews rushed one truck driver, a 34-year-old Salt Lake City man, to an area hospital for treatment of head and facial injuries.

Another semi-truck driver, a 67-year-old woman, was transported by ambulance to an area hospital for treatment of chest injuries, while her 59-year-old husband was flown by medical helicopter to a hospital in critical condition with chest and back injuries. The husband was reportedly sleeping when the crash occurred.

The third truck driver, a 52-year-old Virginia man, was treated at the scene. The man’s passenger, a 49-year-old Maryland man was transported via ambulance to a local hospital for treatment of a back injury.

An investigation into the semi-truck accident is underway.