One person was found dead Wednesday morning in the water under the Interstate 10 Blackwater Bridge, and one is still missing, according to the Florida Highway Patrol.

Divers from the Escambia County Sheriff’s Office assisted in an underwater hunt following a multi-vehicle crash Tuesday night. The U.S. Coast Guard was participating in the search that continued Wednesday.

East Milton Fire Chief Bill Thompson says first responders worked in “cold and chaotic” conditions.

The 7 p.m. crash involved four tractor trailers and a van pulling a U-haul trailer, according to FHP.  It occurred in the westbound lane of I-10 and “one of the tractors traveled over the concrete bridge rail and fell into the water below,” the Florida Highway Patrol said in a news release.

The crash's chain of events was not released by the FHP Wednesday evening. However, emergency radio transmissions revealed the challenges faced by first responders.

The original call of an accident on the bridge went out around 7 p.m. When first responders arrived a few minutes later, a fire department vehicle slid on the ice, scraping the truck on the side of the Blackwater Bridge.  

Ambulances were ordered off the bridge by a Lifeguard Ambulance supervisor after the 4-wheel drive agency vehicle he drove to the scene slid sideways on the icy bridge.

More than one extrication was necessary to free those involved in the accidents. One person was run over by another vehicle, according to Thompson.

More than one 18-wheeler hung over the edge of the bridge, the cab of another fell into the water, and one vehicle was on its side on the bridge when emergency officials arrived.

The fire department scene commander called for the Florida Department of Transportation to bring heavy equipment, including a crane, out to remove the larger vehicles.

FHP says David Mattadeen, 56, of Palm Bay, was driving a 1988 Ford tractor trailer and had minor injuries, the Florida Highway Patrol reported.

William J. Smith Sr., Granbury, Texas, the 64-year-old driver of the U-Haul, was taken to Santa Rosa Medical Center along with his passenger, 85-year-old Dorothy Smith. Both were listed with minor injuries.

Two were missing and considered “possible fatalities in the water,” the FHP report said.

The confirmed death was one of the two missing.

One of the tractor trailer drivers, not yet identified by the FHP, was treated for minor injuries by emergency personnel responding to the scene.

Weather conditions were deteriorating at the time of the accident, the report said.

The bridge was still closed Wednesday, Thompson said.

“There is debris from one end to another,” he said. “They are moving the last two 18-wheelers off the bridge today.”

Emergency crews from Avalon and Bagdad also responded.

Divers are expected to return to the site on Thursday to search for the missing person.

Interstate 10 remained closed from the Alabama State line to Marianna, Florida Wednesday, according to the FHP website.

County officials say a fuel sheen fell into the river from the bridge (as a result of the accident).

While removing the 18-wheeler, part of the cargo in drums fell into the river with other debris.

If the drums are located, citizens are asked to call the Santa Rosa County 9-1-1 center at 983-5372.

The primary content was drums of vinegar.

Daily News Staff Writer Tom McLaughlin contributed to this story.