Two girls, ages 6 and 12, were killed in a Monday night crash near Busby that sent seven other people to the hospital, according to the Montana Highway Patrol.
Big Horn County Coroner Terry Bullis on Tuesday said he is still working to contact the girls' families and has not yet released their names.
The crash occurred before 11 p.m., when a 15-year-old boy driving a GMC Yukon lost control of the truck and hit a culvert, causing the vehicle to roll, according to the MHP report.
Three of the six occupants were ejected. The vehicle had been traveling eastbound on Highway 212, about 4 miles east of Busby in Big Horn County, the report states.
Along with the driver, the Yukon also contained a 5-year-old boy, two girls ages 13 and 15 and the two girls who died, the report states.
None of them were wearing seat belts. The driver and all the passengers were transported to the Indian Health Services hospital in Lame Deer.
The extent of injuries to the surviving passengers was not included in the report, and their places of residence were listed as "unknown."
A call to the MHP trooper investigating the incident was not immediately returned Tuesday morning.
A short time later, a Dodge Stratus was traveling westbound when it struck one of the ejected occupants, according to MHP.
The report does not indicate what happened to the second vehicle, but notes that three female passengers were taken to the Lame Deer hospital with unknown injuries. Two 20-year-old women from Lame Deer were in the car, along with a 21-year-old Billings woman.
Alcohol was possibly a factor in the crash, the report states, but does not indicate which of the drivers was suspected to have been drinking.