A 2-year-old Durango girl died Wednesday after her neck became stuck in an automatic car window, according to the La Plata County Sheriff's Office.
Authorities have not released the name of victim or her family but said they live in Durango.
Sheriff's Office spokesman Chris Burke said a father took his daughter to work on Wednesday at a construction site east of Durango.
The father left the child inside the vehicle - a truck - with the windows down and music playing with the car keys left in the accessory position.
The girl was about a month away from turning 3 years old.
The father was about 50 feet from the car, and regularly checked on the girl while he worked, Burke said. Other people at the work site also kept an eye on the toddler, he said.
At some point, the girl - who was not strapped in and was free to move around - caused the truck window to roll up, and in the process, her neck became trapped, Burke said.
He said it is unclear how much time passed from when the window clamped down on the girl's neck and when she was discovered and released.
Once discovered, workers at the construction site began performing life-saving procedures on the girl. Authorities were notified of the incident just before 11:30 a.m., and paramedics arrived soon after, Burke said.
The toddler was taken to Mercy Regional Medical Center in Durango and eventually flown to a Denver hospital, where she died from her injuries, Burke said.
La Plata County Coroner Jann Smith said she has not determined an official cause of death; an autopsy will be performed Monday. She also declined to release the name of the family pending completion of the autopsy.
Burke said no charges are pending against the father and the incident remains under investigation. "This was accidental, because both windows were open and the father was checking on the child," Burke said.
"If windows were up, that would be a different situation probably. It's just a terrible accident."