A western Wisconsin girl participating in a state-sponsored snowmobile safety course accelerated off the course outside Osceola High School, crashed into a loading dock and died despite her mother’s lifesaving efforts, authorities said.

The crash occurred shortly after 9 a.m. Saturday, killing Sarah Thorsland, 13, police said.

Sarah attended middle school at the building next door to where the incident occurred and died the following day at Gillette Children’s Hospital in St. Paul.

An initial inspection of the snowmobile revealed no immediate explanation for what police termed a “rapid acceleration” during the Wisconsin Department of Natural Resources class.

Police Chief Tim Lauridsen said half of the class of 42 had completed the slow-speed maneuver course without incident — taking turns on the same snowmobile — when the crash occurred.

The front of the snowmobile was outfitted with wheels on the skis, equipment supplied by the machine’s manufacturer, to best simulate being on snow as it rolled along the pavement outside the school, Lauridsen said.

Anyone ages 12 to 18 in Wisconsin must take a safety certification course before being allowed to operate a snowmobile on public trails, lands or frozen waters.

According to police:

Sarah, who was wearing a helmet, had been negotiating a pattern of traffic cones when her snowmobile accelerated and struck the loading dock. After the snowmobile crashed, Sarah’s mother, a nurse at Osceola Medical Center, joined first responders to give the child medical attention.

Sarah was taken by air ambulance to Regions Hospital in St. Paul and then transferred to neighboring Gillette Children’s Hospital, where she was put on life support.

A Facebook page in Sarah’s memory said “she was beautiful and kind and just an outstanding young lady.”