Two people died and two were injured in separate accidents on Utah highways Monday.

Killed were:Timothy R. Potter, 39, Gardnerville, Nev.

Randall Smith Brooksby, 21, Santa Clara.

- Potter and his passenger, Cache Hadley, 21, Bountiful, were traveling south on I-15 in Iron County near Cedar City about 10:50 a.m. Monday, when Potter apparently fell asleep and lost control of the vehicle, said Utah Highway Patrol Sgt. Steve Esplin.

The vehicle rolled several times, and Potter was ejected. He was taken to Fillmore Hospital, where he was pronounced dead.

Hadley, who was wearing a seat belt, suffered minor injuries and was also taken to Fillmore Hospital, where he was treated and released, a hospital spokeswoman said.

- In Salt Lake County, Brooksby and Cody A. Mair, 22, Payson, were in a construction truck hauling a load of tar just north of the 10600 South overpass on I-15 about 7:20 p.m, when the truck began to fishtail, UHP Lt. Verdi White II said. The truck is owned by Bonneville Asphalt, White said.

The truck veered off the right shoulder of the highway and rolled, crushing the cab and trapping the two men inside.

Brooksby, who was driving, was pronounced dead at the scene. Mair was taken by medical helicopter to LDS Hospital in critical condition. He remained in critical condition in the intensive care unit Tuesday morning, hospital spokesman Jess Gomez said.

Traffic was diverted for several hours on the freeway.