Six people were killed and one was injured Thursday morning when a tractor trailer carrying yogurt rear-ended a vehicle that had slowed for construction work, causing a chain reaction. 

Five of the victims died when their SUV caught fire after being hit. Trooper Jack Keller told The Associated Press that the driver of the first vehicle struck died at a hospital.

The tractor-trailer driver,  James A. Mills Jr. of Myerstown, Pa., was taken to a hospital for treatment, the AP said.

The AP reported the tractor-trailer was heading down Route 11 in Antwerp, a town 90 miles north of Syracuse and a few miles from the Canadian border, when it hit the back of a vehicle causing it to collide with a Department of Transportation truck and the SUV.

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State police told the AP the SUV was moving slowly or was stopped because of roadwork. 

The road, a two-lane stretch of highway, had signs warning motorists that crews were conducting road work ahead.

It is not known if the five occupants inside the SUV were all related, police told the AP.

The AP reported a DOT spokesperson said a crew was repaving the road and that an agency employee had been airlifted to a hospital. His condition was not known. 

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The tractor-trailer was carrying yogurt from a nearby plant to a neighboring county at the time of the accident, according to the AP. 

Troopers told the AP reported  that Mills will be tested for drugs and that they were inspecting the trailer for mechanical problems. 

The Jefferson County district attorney will determine if charges will be filed. 

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Federal transportation officials have shut down 26 bus operators in the Northeast corridor after a year-long investigation found that the companies posed an "imminent hazard" to public safety.

The Department of Transportation, which oversaw the investigation, called the shutdown orders the "largest single safety crackdown in the agency's history" in a press release issued Thursday.

The action applies to nine active bus companies, 13 companies that had been ordered out of service but continued to operate and three companies that had applied to become operators, as well as one ticket seller. The companies were primarily run by Apex Bus, Inc., I-95 Coach, Inc. and New Century Travel, Inc. and collectively transported more than 1,800 passengers daily from New York to Florida along Interstate 95.

The carriers had multiple safety violations, according to safety investigators. The companies employed drivers without valid commercial driver's licenses, failed to create drug and alcohol testing programs and operated buses that had not been routinely inspected and repaired.

The investigation began last year after a series of deadly bus crashes along I-95.

Related: Deadly bus crashes highlight safety issues

The companies cited in the investigation will not be allowed to operate under another name in the future under a new rule that revokes the carrier's operating authority and matches new companies to ones previously shut down.

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