Idaho State Police said two children were killed and the 16-year-old driver was hurt in a one-vehicle rollover on Interstate 15 on Friday afternoon near the Blackfoot rest area.
According to police, the Chevrolet Impala went off the roadway, hit lava rock in the median and rolled, ejecting all three people.
Police say the children were ages 8 and 10.
The 10-year-old was pronounced dead at the crash. The 8-year-old died at Eastern Idaho Regional Medical Center.
The teen driver was taken to EIRMC as well. His condition is unknown.
Police said in a news release Friday evening that the children were not wearing seat belts.
Local News 8 will not release name of the driver because he is a minor.