AVALON PARK, Fla. -

An 18-year-old driver who troopers believe was high on K2 struck and killed a bicyclist in Avalon Park, according to the Florida Highway Patrol.

The crash happened Sunday afternoon on South Avalon Park Boulevard near Tea Rose Drive.

Troopers said Anthony Moffa, 18, hit Forrest Flaniken, 53, while Flaniken was riding in a bicycle lane.

After striking Flaniken, Moffa crashed into a tree in the center median and tried to flee the accident, troopers said.  Bystanders were able to keep Moffa at the scene until police arrived.

Officials said Moffa is suspected to have been using K2, a synthetic marijuana, at the time of the crash.

A witness said she and her husband witnessed the crash.

"The driver came out of the car, staggered down the road ... obviously, he was very shaken up," the woman said.

Moffa was arrested on charges of DUI manslaughter, vehicular homicide and leaving the scene of a crash.

Watch Local 6 News for more on this story.