At 6:30 a.m., authorities say the two women were on the side of the highway changing a flat tire when they were struck by the semi.
The truck was going westbound on Interstate 70 just east of Limon.
According to Colorado State Patrol, one woman died on scene. The other woman was airlifted to a hospital and later died.
The semi truck pulled over about a half-mile away from the crash scene, according to Sgt. Mike Baker with Colorado State Patrol.
According to CSP, the occupants of the semi were an adult male and a juvenile male.
According to officials, prior to their arrival at the scene, the juvenile was transported from the scene by a private party.
When law enforcement arrived, the adult male, Michel Martin, 37, told them he was driving the semi truck. However, upon further investigation, the juvenile was determined to have been the driver.
The victims were identified as 48-year-old Shun Jones of Carrollton, Texas and 38-year-old Amanda Omo-Iyamu of Balch Springs, Texas.
An 18-year-old was in the car when the accident happened. He was not injured.
The juvenile driver was charged with two counts of failing to remain at the scene after an accident involving death, which is a felony. He was also charged with two counts of careless driving caused death, which is a misdemeanor.
Martin was charged with one count of false reporting, which is a misdemeanor.
Both were booked into the Lincoln County Jail. The juvenile may be moved to a juvenile assessment center.
Baker says alcohol and drugs are not believed to be contributing factor in the crash.
Changing a tire on the side of any road or highway can be dangerous. The National Safety Council has some tips on what you can do if you have a blowout.
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