The driver of a fuel truck clipped a sedan, causing his tanker to ignite in a ball of fire Saturday morning on the Long Island Expressway between exits 48 and 49, according to the Suffolk County Sheriff's Department.

"It would appear that the driver of the truck was not able to get out of the vehicle," Chief Michael Sharkey of the Suffolk Sheriff's Department said.

The crash in the eastbound lanes at Exit 48 and the intense fire caused a highway sign structure to collapse onto the roadway, forcing the closure of both sides of the expressway. Nassau County police said that the eastbound LIE traffic was being diverted at Exit 46 and advised motorists to use alternate routes.

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The female driver of the sedan clipped by the tanker was injured and taken by helicopter to Nassau University Medical Center in East Meadow. The extent of her injuries was unclear.

Officials said the first report of the crash near the Nassau-Suffolk border at Round Swamp Road came at 8:06 a.m. The truck appeared to be a 18-wheeler with a liquid tanker carrier, police said. Both sides of the expressway were closed, as was at least one service road.

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A huge sign that includes HOV directions and spans the six lanes, eastbound and westbound, was brought down in the crash and blocked the entire expressway, indicating the roadway could take hours to make passable.

As of 9:30 the Long Island Expressway was closed to traffic in both directions between exits 48 and 49, with vehicles being diverted to the service road. Flames and black smoke rose into the air from the wreckage of the overturned tanker.

The size and intensity of the crash triggered a massive emergency response from law enforcement and emergency personnel from both counties. A foam-retardant-equipped truck from Long Island MacArthur Airport responded to help put out the fire. Firefighting units and authorities on the scene included the Long Island MacArthur Airport fire rescue team, Melville fire department, New York State police, the Suffolk Sheriffs Department, Nassau police and Suffolk police.