A 20-year-old University of Denver student was killed in a rollover after she apparently fell asleep while driving on I-80 in northern Utah, the Utah Highway Patrol says.

The patrol said Sandra Johnson, a resident of Bermuda, drifted off the road about 9:45 a.m. Monday about 25 miles east of Salt Lake City.Passengers Carolyn Pulichino, 20, Wellesley, Mass., and Melissa Hila, 19, Avenel, N.J., were flown by emergency medical helicopter to University of Utah Hospital in Salt Lake, the UHP said.

Pulichino was listed in critical condition Tuesday, a hospital spokeswoman said. Hila was treated and released.