A bus slammed into six vehicles on Interstate 95 in Virginia as traffic slowed for a work zone, killing five people and sending 34 to hospitals.

The crash happened at about 2:35 a.m. on southbound I-95 in Stafford County. All five of the people who died were in vehicles hit by the bus, and three of the injured are in critical condition, police said.

“The preliminary investigation indicates that traffic was slowing southbound for an upcoming work zone,” state police said in a news release. “A bus failed to slow for traffic and struck six vehicles.”

It was not immediately known what the bus was being used for or how many people were aboard.

Five people were killed and 34 others wounded after a bus struck multiple vehicles on Interstate 95 in Virginia (Virginia State Police via AP)

“We’ve got patients in multiple hospitals. We’ve got the driver at a hospital here,” said Peyton Vogel, a Federal Transit Administration spokesperson who was on the scene. “I’ve got to say, this is one of the most tragic things I’ve ever seen. Absolutely tragic.”

Mary Washington Healthcare said it received 19 patients from the crash. It posted online that seven of the patients were taken to its trauma center in Fredericksburg, where four were being discharged and three remained in treatment — one in serious condition and two in critical condition. Twelve were taken to its hospital in Stafford, where they were later discharged in good condition.

The crash is under investigation and charges are pending, police said.

The National Transportation Safety Board posted online Friday that it was sending a “go-team” to conduct a safety investigation into the crash and that it would have a spokesperson at the scene.

Traffic was slowing for an upcoming work zone when the bus slammed into six cars (Virginia State Police via AP)

The southbound lanes had reopened by noon Friday, but traffic was still backed up for a couple of miles, according to a state transportation advisory.

While it is too soon to say what caused Friday’s crash, federal authorities have been grappling with interstate passenger bus safety issues for decades.

Following a series of passenger bus crashes in 2008 that killed 41 people, the U.S. Department of Transportation published a Motorcoach Safety Action Plan.

The NTSB investigated 16 fatal motorcoach crashes between June 1998 and January 2008, finding that driver-related problems such as fatigue, medical condition, and inattention accounted for 56 percent of the accidents. The agency said driver-related problems were responsible for 60 percent of the fatalities in those crashes.

Among the actions recommended were creation of a pre-employment driver history screening program, and a national drug- and alcohol-testing database “to enable motorcoach operators to determine if drivers have a history of violating DOT alcohol or drug rules.”

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