ST. AUGUSTINE, Fla. -

At least six people were killed in two separate crashes that closed Interstate 95 south in both St. Johns and Flagler counties for hours Saturday evening.  At 1 p.m.  Sunday, two of three southbound lanes of I-95 at State Road 206 were open but the Florida Highway Patrol continued to encourage people to avoid the area.

The FHP says two people were killed in the first crash, which happened around 5:30 p.m. at Mile Marker 288, south of Palm Coast Parkway in Flagler County.  

Backed up traffic from that crash is believed to have contributed to the second crash about 7:40 p.m., where a tractor-trailer apparently rear-ended a car, causing a chain-reaction crash and starting a fire that engulfed several vehicles. Troopers say at least four people died in this crash and fire.

In the Flagler County crash, troopers say 38-year-old Roy White, of Jacksonville, was driving a Chevrolet Silverado north on I-95 and for some reason drifted across the highway. That car hit the median and became airborne, traveling over a guardrail, and entered southbound lanes of I-95.

White's car hit the top of the Honda Civic driven by 56-year-old Pamela Taylor Thor, of St. Augustine, and then a third car.

Troopers say White's passenger, 17-year-old Benjamin Smith, who was not wearing a seat belt, was ejected from the truck.  Both Smith and Thor died from their injuries.

No one in the third car was hurt.

Troopers originally closed I-95 in both directions, but reopened northbound lanes around 7:15 p.m.

IMAGES: Fiery pileup in St. Johns County

FHP said the backup from the Palm Coast crash may have contributed to the crash in St. Johns county that involved at least eight passenger vehicles and three commercial motor vehicles. At least four deaths were confirmed.

FHP said preliminary information revealed that traffic was being detoured from I-95 southbound to the exit of U.S. 1, due to the Palm Coast crash. Traffic was stopped awaiting the detour when a semi-truck approached the area.

For reasons still under investigation, the big rig was unable to stop in time to avoid rear-ending a vehicle, which started a chain-reaction crash involving nearly a dozen vehicles.  After the initial impact, fire engulfed several vehicles.

The names of the crash victims have not been released.

Just before noon, the FHP said one southbound of I-95 at S.R. 206 in southern St. Johns County was reopened and a second lane reopened within the hour, but troopers urged people to avoid the area until the highway was completely cleared. 

Fiery pile-up in St. Johns County

Published On: Jun 01 2014 09:09:10 AM EDT   Updated On: Jun 01 2014 11:46:33 AM EDT

A backup of I-95 southbound traffic after a later-afternoon crash in Palm Coast is believed to have led to a pileup of 11 vehicles in southern St. Johns County that sparked a fire and killed at least four people.

Smoke from fiery crash on I-95
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Photo from Suzanne Morea

The FHP says a tractor-trailer apparently rear-ended a car about 7:40 p.m. south of Florida 206, causing a chain-reaction crash.