ST. CROIX COUNTY, Wis. - Authorities say a fatal crash that killed a 16-year-old girl was caused by a woman who had both hands on her phone while driving.

The updated information comes from the St. Croix County Sheriff's Office, who on Monday said witnesses told officers that a woman driving north on State Highway 35 had both of her hands on her phone and drifted into the adjacent lane of traffic, causing the teen driver to crash.

Authorities responded to the scene of the crash around 3:21 p.m. on Friday, on the 400 block of Highway 35 in the town of Troy and found a 2004 Oldsmobile Bravada in the ditch.

The preliminary investigation reveals a 2007 Ford Taurus that was being driven by a 21-year-old woman from Big Lake drifted into the lane occupied by the teen driver, identified as Kyra Faith Hayes of Beldenville, Wis., causing her to swerve suddenly and lose control of the Oldsmobile.

The vehicle then rolled several times, ejecting Hayes. She was pronounced dead at the scene.

Authorities say Hayes was not wearing her seat belt.

The two vehicles never collided and the 21-year-old driver was not injured. Authorities say the woman turned around and returned to the scene of the crash. Her passenger, a 22-year-old from Minneapolis, was also not injured.

The crash remains under investigation by the St. Croix County Sheriff's Office and the medical examiner's office.

This is the county's fifth traffic fatality of the year.

A GoFundMe page has been set up for Hayes, who was a sophomore at Ellsworth High School, to help cover funeral expenses.

"This beautiful girl was taken from us far too soon, and her light and beauty will be missed terribly," the page states.