A 16-year-old from St. Augustine was killed in a head-on crash on A1A on South Ponte Vedra and Beach Side Drive Thursday, the Florida Highway Patrol said.
A man and woman, both 53, from Jacksonville were seriously hurt.
The FHP report said the 16-year-old driver was traveling northbound on A1A, when he crossed the center line and hit a pick-up truck that was traveling southbound.
It happened around 4 p.m. on Thursday.
Troopers said everyone had their seatbelt on.