A minivan carrying nine people rolled and crashed on Interstate 70 in Utah, killing four people and injuring four others.
Police are investigating whether the vehicle was involved in human smuggling. They were searching for one person who was in the van but ran off after the wreck early Friday about 30 miles from the Colorado line.
Authorities said four passengers were thrown from the 1999 Toyota Sienna as it rolled down the median.
Utah Highway Patrol Sgt. Todd Royce said investigators don't know what caused the crash, but they believe no other vehicles were involved.
Royce said the survivors apparently do not speak English. They were taken to a hospital in Grand Junction, Colorado. Their injuries ranged from serious to critical.