The driver of a bus in a crash that killed five people in Virginia on Friday, including a family of four en route to a relative’s wedding, has been charged with involuntary manslaughter.

Jing S. Dong, 48, of New York City, was charged Saturday with two counts of involuntary manslaughter, and more charges were pending, Virginia State Police said in a statement. He was arrested and remained in custody while hospitalized with unspecified injuries, according to a statement from prosecutor Eric Olsen, the commonwealth’s attorney for the area where the collision occurred.

State police described the family of four as a 7-year-old boy, a 13-year-old girl, a 44-year-old woman and a 45-year-old man, all from Greenfield, Massachusetts.

The fifth victim was identified by state police as 25-year-old Priscilla R. Mafalda, of Worcester, Massachusetts. She was driving a Chevrolet Suburban that was hit by the bus on southbound Interstate 95 before striking the Acura the family was in, state police said.

Mayor Virginia Desorgher of Greenfield, a city of nearly 18,000 people about 100 miles west of Boston, said in a statement: “No words that can fully ease the weight of this sudden and unimaginable grief.”

She told the family’s loved ones that “you are not walking through this dark time alone.”

Olsen said Dong was ordered by a magistrate to be held without bond until he is released from the hospital and is able to appear in court.

“I have determined that probable cause presently exists to establish that the driver of the tour bus caused this crash and, at the time of the crash, he was driving in a criminally negligent manner,” Olsen said.

Each count of felony involuntary manslaughter carries a maximum sentence of 10 years, he said.

It was not clear Saturday whether Dong had retained legal representation. The state public defender for Stafford County did not immediately respond to a request for comment Saturday.

Federal investigators said they are examining whether fatigue, impairment, medical issues or other factors played a role in the crash.

The National Transportation Safety Board said Saturday that a six-member team has joined the investigation into the crash in Stafford County, about 40 miles south of Washington, D.C.

Investigators will review the driver’s actions in the 72 hours before the collision, including possible sleep issues and potential drug or alcohol impairment.

“We are particularly interested in issues relating to, first, motor coach driver factors, including fatigue, impairment, qualifications and medical events,” NTSB member Tom Chapman said at a news conference. “Highway factors, including work zone designs, whether variable speed limit signs were used, and whether the end of the traffic queue was monitored.”

The crash occurred at around 2:35 a.m. when the bus failed to slow and struck as many as six vehicles near the 146-mile marker in Stafford County, state police said in a statement Friday.

An additional 44 people were hospitalized with injuries, three of them in critical condition, police said, adding that about 34 people were on the bus, though they did not break down the injury status of those on board.

Investigators are also trying to determine whether the bus driver attempted to brake before impact.

“It seems fairly clear that if there was any braking, there wasn’t much, because of the speed and the severity of the collision,” Chapman said. “But too early yet to know exactly what was happening on board the vehicle.”

Virginia State Police said the preliminary investigation showed that traffic was slowing southbound on Interstate 95 for a work zone when the bus failed to slow down, triggering the fatal crash.

The bus was headed from New York City to Charlotte, North Carolina, police said. NBC News was unable to find contact information for someone with the driver’s name in New York City.

The bus operator is E&P Travel, police said. It is listed by the Federal Motor Carrier Safety Administration as a company in Kings Mountain, North Carolina, with four buses and 11 drivers.

Administration data lists four violations for the company, three related to allegations of driving a motor coach or bus 15 or more mph above the speed limit and one for a motor coach driver who allegedly could not satisfy English proficiency requirements.

Additionally, the administration lists an E&P bus’ involvement in a 2024 crash in which nine were injured; fault is not indicated. E&P had no acute or critical violations on record that would demand an expedited inspection or intervention, the administration’s data shows.

The company did not immediately respond to a request for comment.

The NTSB’s investigation comes after Transportation Secretary Sean Duffy said the bus operator will face scrutiny and characterized the driver as an immigrant with limited English proficiency. Chapman said Saturday that the NTSB is “still assessing the driver’s language proficiency” and has not drawn a conclusion on the matter yet.

The NTSB expects to publish a preliminary report in a month, Chapman said. The final report will take anywhere from a year to two years to complete.

“Our investigators will work thoroughly to document relevant evidence and gather additional factual information,” Chapman said. “Our mission is to understand not just what happened, but why it happened, and to recommend changes to prevent it from happening again.”