Updated

Calls from victims of a pileup on a Florida highway that killed 10 people describe the chaotic scene to dispatchers in 911 recordings released Monday.

A stretch of Interstate 75 near Gainesville had been closed due to low visibility caused by smoke and haze. Just fifteen minutes after reopening, at least a dozen cars, six tractor-trailers and a motorhome collided on the roadway.

One caller, who was on the smoke-filled scene as the cars began piling up, spoke to an operator about the crashes.

When the 911 operator asked how many crashes she had seen so far, the caller replied, "We cannot see. This is the third one now already."

The sound of cars colliding is audible in the background.

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Another caller told a dispatcher that the fog and smoke was so thick they couldn't see.

"The smoke is very thick you can see obviously only your hand in front," the caller said. "I do hear an ambulance or police officer coming down the road."

When rescuers first arrived to the crashes, they could only listen for screams and moans because the poor visibility made it difficult to find victims in wreckage that was strewn for nearly a mile.

The Florida Highway Patrol said Monday that conditions were clear enough when they decided to reopen the interstate highway where 10 people later were killed in two deadly pileups amid thick smoke from a 62-acre brushfire and fog.

"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," highway patrol spokesman Lt. Patrick Riordan said in a news conference.

Yet after the highway reopened early Sunday morning, visibility along that section of Interstate 75 near Gainesville quickly began to deteriorate, Riordan said. The crashes began shortly after.

"Factors changed quickly," Riordan said. "Drivers have to recognize that the environment changes. They have to be prepared to make good judgments."

At least a dozen cars and six tractor-trailers were involved, some vehicles burst into flames. Three bodies were so badly burned they haven't been identified yet, he said. No names of victims have been released pending notification of relatives, Riordan said.

When asked about why the highway was reopened with the brushfire still burning, Riordan said: "I'm not going to play a what-if situation."

About midnight Sunday, the highway patrol closed the section of I-75 for more than three hours after a pileup happened when the highway became impassable from fog and smoke from the nearby brushfire.

Troopers inspected the highway before a sergeant and lieutenant made the decision to reopen I-75 about 3:30 a.m., he said. Fifteen minutes later, the fatal pileups began on both the north and southbound sides of the highway.

Riordan declined to release the two troopers' names or provide details on their careers with the highway 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. They also will assess whether the NTSB should formally join the probe, which is being led by the highway patrol.

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.

The Associated Press contributed to this report.