An 18-year-old Napa teen has been identified as the driver killed in a single-car crash on Highway 29 Sunday night, said Napa Sheriff's Office Capt. Tracey Stuart.

Dayton William Lane Moore, a former Napa High School student, was driving a Toyota Highlander northbound on Highway 29 when, "for some unknown reason," he veered off the roadway, struck a metal streetlight, then continued east until he slammed into a tree and a fence near the intersection of Sierra Avenue, said Napa City Fire Truck Captain Scott Sedgley.

Moore was pronounced dead at the scene. The crash was reported at 7:24 p.m. There were no passengers in his vehicle, Sedgley said.

The driver's side of the SUV was caved in, requiring emergency responders to remove the door with pry bars so they could reach Moore, Sedgley said. The driver was wearing a seatbelt.

The metal streetlight fell across both northbound lanes, causing the car behind Moore to roll over it and pop all four of its tires, he said. There were no other injuries or damages reported.

Highway 29's two northbound lanes were closed between Trancas Street and Trower Avenue for five hours so Napa police could conduct their investigation.

An autopsy was scheduled for Monday afternoon at the Napa County Coroner's Office.

Moore, a senior, attended Napa High School until February 2010, then transferred to Napa Valley Alternative School until December 2010.

A dozen grieving Napa High students had approached student services for counseling Monday, said Annie Petrie, assistant principal of student services.

"It's very overwhelming and sudden to them," Principal Barbara Franco said. "This is an extremely difficult time for his family, and we want to extend our sorrow to them."

Moore loved the drama program at Napa High, said Petrie, who sent counselors to talk to drama students about Moore's death.

"He had a great group of friends," Petrie said. "He was always smiling, and just a real care-free young man."

His junior yearbook picture shows Moore with a full head of strawberry curls and a relaxed grin.

On his Facebook page, Moore listed his interests as longboarding, photography, graffiti and family. He posted a collection of quotes from figures as diverse as Jack Johnson and Yoda.

"One death is a tragedy," he quoted from Joseph Stalin, "one million is a statistic."