An elderly motorist crashed after losing control of his vehicle near the intersection of Avalon and Bridge Street in Kuna just before 4 p.m. Thursday.
The 82-year-old man, who was not wearing a seat belt, suffered life-threatening injuries, according to the Ada County Sheriff's Office. Paramedics rushed him to St. Alphonsus Regional Medical Center for treatment.
Investigators say the small Nissan pickup hit a sign, a fence and a large tree before coming to rest against a second tree.
Initial information suggests the man may have had a medical emergency before the crash, sheriff's investigators say.
Sheriff's officials said there was no one else in the man's vehicle, and no other vehicles were involved in the crash.