Published: Feb 01, 2013 12:26 PM EST
Updated: Feb 01, 2013 6:23 PM EST

COLLIER COUNTY, Fla.- A 17-year-old was driving an ATV on 19th Street NW, near Golden Gate Blvd., when he tried to avoid a dog and was thrown from the vehicle. John Boot remains in serious condition at Lee Memorial Hospital. It was the teen's friend who made that terrifying phone call after Boot flipped his four-wheeler right in front of a Golden Gate home.

FHP says the teenager was riding illegally because it was a public roadway. He was trying to avoid a dog when he flew off the vehicle. According to FHP, Boot was not wearing a helmet at the time and sustained head trauma in the accident.

In Florida, only riders under the age of 16 are required to wear a helmet.