GAINESVILLE, Fla. — Minutes before two pileups killed 10 people on a highway shrouded in fog and thick smoke from a brush fire, the Florida Highway Patrol had reopened the always busy six-lane interstate after an earlier serious accident. A sergeant and lieutenant determined after about three hours that conditions had cleared enough for drivers, but visibility quickly became murky again, officials said Monday.

At least a dozen cars, six tractor-trailers and a motorhome collided at about 3:45 a.m. Sunday. Some cars were crushed under the bellies of big rigs. Others burst into flames and sent metal shrapnel flying through the air, horrifying witnesses watching the violence along Interstate 75 in calls to 911. Eighteen survivors were hospitalized.

In a 911 recording released Monday, a driver and her passengers told a dispatcher that the fog and smoke from the 62-acre brush fire was so thick they couldn’t see.

“I think there was another accident behind us because I heard it,” a woman said. “Oh my gosh, it’s so dark here.”

Highway patrol spokesman Lt. Patrick Riordan confirmed on Monday evening the names of four people who died in the crash: Pastor Jose Carmo Jr., Adriana Carmo, Leticia Carmo and Edson Carmo.

Jose and Adriana Carmo were married and Leticia was their daughter, said Arao Amazonas, senior pastor at their church, the Igreja Internacional de Restauracao, or International Church of the Restoration.

The couple’s younger daughter, Lidiane, was injured in the crash, Amazonas said. A hospital spokeswoman said Monday afternoon that she was listed in critical condition.

Amazonas had been at a religious conference in Florida with the family and many others since Thursday. He said he spoke with the pastor before the family left Florida on Saturday night and urged him to wait until morning, he said. But Carmo told him he wanted to be back in time for the Sunday morning service.

The Carmos were in one van and other church members were in a second van. The passengers of that van called Amazonas after the accident to tell him what happened, he said.

About 100 people gathered Monday evening at the suburban Atlanta church, which caters to the local Brazilian community, to mourn the deaths of their fellow church members. People at the gathering wailed and wept as Amazonas addressed them in Portuguese.

“We couldn’t have imagined such tragedy would come to us,” Amazonas said.

Riordan declined to release the names of the two troopers who made the decision or provide details on how long they had been with the patrol. He said no troopers have been disciplined but the investigation into the crash continues. National Transportation Safety Board officials said Monday they are sending investigators to the scene. Gov. Rick Scott also called for an investigation.

“We went through the area. We made an assessment. We came to the conclusion that the road was safe to travel and that is when we opened the road up,” Riordan said in a news conference. “Drivers have to recognize that the environment changes. They have to be prepared to make good judgments.”

In the same 911 call, another woman took the phone and screamed an expletive as she hears another crash.

“That was a truck. We cannot see. It’s like impossible to see,” the caller said. “The smoke is very thick you can see obviously only your hand in front. I do hear an ambulance or police officer coming down the road.”

Hours later, twisted, burned-out vehicles were scattered across the pavement, with smoke still rising from the wreckage. Cars appeared to have smashed into the big rigs and, in one case, a motor home. Some cars were crushed beneath the heavier trucks.

Reporters who were allowed to view the site saw bodies still inside a burned-out Grand Prix. One tractor-trailer was burned down to its skeleton, charred pages of books and magazines in its cargo area. And the tires of every vehicle had burned away, leaving only steel belts.

The Florida Forest Service said Monday it still had not determined if the fire was intentionally set or accidental, although lightning has been ruled out. Spokeswoman Ludie Bond said the fire is contained but was still burning. Firefighters are spraying water around its perimeter attempting to reduce the smoke.

Criminal defense attorneys said that if the fire was caused by arson, authorities likely will file charges of manslaughter and possibly felony murder, which is defined as a death that happens as result of participating in a felony.

“You can bet they will be,” said Brian Tannebaum, a former president of the Florida Association of Criminal Defense Lawyers.

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