A rural Lodi family is mourning the loss of a son and nephew whose "smile could set the world on fire," according to the boy's uncle, Dan Nellen, after an all-terrain utility vehicle rollover west of Lodi last week.

Columbia County officials are blaming the death of 17-year-old Trevor Nellen on a lack of protective equipment, and said excessive speed and alcohol were not factors in the accident.

Authorities were called to a rural Lodi farm along Highway 60 at 5:15 p.m. Thursday following a 911 report of an ATV accident. Lodi EMS arrived on scene to find Trevor critically injured after being thrown from the vehicle.

Columbia County Medical Examiner Marc Playman said Trevor had been riding in the vehicle with a 16-year-old friend and a 15-year-old resident of the property. The 15-year-old was operating the vehicle and lost control, causing the ATV to roll.

All three boys were thrown from the vehicle, Playman said. Trevor was pinned under the ATV and suffered a "severe head injury," while the other two boys were thrown clear and not injured.

The ATV the boys were riding in was a Gator utility vehicle made by John Deere.

"A Gator like that is equipped with a seat belt," Playman said. "Based on my training and experience, a seat belt or a helmet would have helped quite a bit."

First-responders arrived to find the vehicle removed from Trevor.

Playman said the boy was placed in an ambulance to be taken to Sauk Prairie Memorial hospital, but died en route. He was pronounced dead upon arrival at the hospital.

Dan Nellen, one of the boy's uncles, said his nephew was at his friend's house playing Thursday afternoon following the boys' last day at school.

Trevor had just completed his junior year at Lodi High School.

"He was your average 17-year-old," Dan Nellen said. "He loved the river - floating, skiing, wakeboarding, snowmobiling. ... The tragedy is his smile will never be there for us again."

Dan Nellen said services for Trevor are being held tomorrow at Dekorra Lutheran Church.

"I was always telling him to slow down," said Jeffrey Raether, another of the boy's uncles who used to snowmobile with him regularly. "He had a passion for speed, though."

"He was a good friend," Raether said. "He was a good boy, and it shouldn't have happened like this."