State Police said the accident happened about 3:30 p.m. on Campti Bayou Road, when a 16-year-old lost control of his 1988 model truck and left the road at a high rate of speed.
A 16-year-old passenger died of injuries and a 15-year-old was hospitalized.
The driver, to be charged with negligent homicide, had minor injuries.
The names of all three were withheld, as was the gender of the two passengers as well as the place of residence of all three.
No one in the truck was wearing a seat belt, troopers said.