Tyler Jensen, the 4-year-old child who had been in Children's Hospital of Denver since last week, died Tuesday morning, according to the Mesa County Sheriff's Office.

Authorities working the case were officially notified of Tyler's death Tuesday morning, but there are still many questions to be answered as they continue their investigation.

Tyler's 2-year-old brother William Jensen passed away on Tuesday, November 27, when he and his brother Tyler were apparently left in their mother's car on the Grand Mesa.

The Mesa County Coroner completed William's autopsy on November 28, but the results aren't available pending the ongoing investigation.

Tyler was taken to St. Mary's Hospital the evening of November 27, before being airlifted to Children's Hospital in Denver.

He was fighting in the hospital for close to a week before the tragic news came Tuesday morning.

No additional information will be released at this time.