The death of a 23-month-old whose body was pulled from the Big Thompson River has been ruled an accident, the Larimer County Coroner's Office announced Tuesday.

The toddler's mother told investigators that on Monday around 9:30 a.m., she fell asleep inside the cabin off U.S. 34 near Drake. She says when she woke up, the door was ajar and her daughter was gone.

Thirty minutes later, David Moore, a spokesperson for the Larimer County Sheriff’s Office, says one of the first responders called to the scene pulled the child from the water downriver.

The toddler's cause of death was drowning with hypothermia as a contributing factor, according to an autopsy.