Two adults died and at least one child was airlifted for medical treatment after a vehicle carrying five people veered off a Colorado highway Tuesday in mountainous terrain, authorities said.

According to initial reports, the vehicle fell between 200 and 300 feet down a cliff in Larimer County, Colorado State Patrol Chief Officer Gary Cutler said.

There were two adults, both of whom died, and three children in the vehicle, Cutler said. One of those children was airlifted to a hospital, he said.

The rollover accident happened around 8:30 p.m. in the area of ​​Pingree Park Road, the Larimer County Sheriff’s Office said in a statement.

The area was described as difficult terrain and some details remained unclear Tuesday night. Cutler wasn’t sure if the other two children had any injuries.

Officials expected to release more information Wednesday morning as more became known, he said.

Larimer County Emergency Services and Larimer County Search and Rescue, Inc., were among those who responded to the incident.

What happened and its cause remained under investigation Tuesday night, authorities said.