A charter bus failed to slow down when it came upon a line of vehicles stopped in an overnight work zone on Interstate 95 in Virginia last month, rear-ending and killing a Worcester woman in her SUV and a family of four from Greenfield in their SUV, national transportation officials said Thursday.

The driver of the 57-passenger motorcoach, Jing Sheng Dong, was swiftly charged with involuntary manslaughter after the multi-vehicle crash on May 29.

The Massachusetts residents did not know each other yet their vehicles were stopped together in the work zone on southbound I-95 in Stafford, Va. at 2:32 a.m. that Friday.

Priscilla R. Mafalda, 25, of Worcester, was a passenger in a 2021 Chevrolet Suburban that was in the direct path of the 2013 Van Hool C2045L motorcoach. She was traveling with her husband to South Florida.

Also in the path of the charter bus was the Doncev family, a mother and father from Greenfield traveling with their 14-year-old daughter and 7-year-old son to a family wedding in South Carolina. Their 2020 Acura MDX was consumed by fire, the report from the National Transportation Security Board said.

In all, eight vehicles were involved, with dozens of people injured and hospitalized.

The bus, occupied by Dong, 48, who worked for E&P Travel, Inc., and two dozen passengers, was en route from New York City to Charlotte, NC.

The conditions were clear and dry on the six-lane roadway where three southbound and three northbound lanes were divided by two reversible express toll lanes, the NTSB report said.

An overnight repaving project had prompted the closure of the southbound center and right lanes, as well as the right shoulder, according to the report.

When the charter bus approached from the south in the center lane, it failed to slow done for stopped traffic, the report said. It did not say how fast the bus was estimated to be traveling.

The motorcoach continued to travel south for nearly a half mile, causing a chain-reaction crash into eight vehicles, the report said.

The overnight work zone was scheduled to conclude at 5 a.m., less than three hours from the time of the fatal crash, the NTSB said.

The investigation is ongoing while the NTSB determines probable cause.

The ​Virginia State Police, Virginia Department of Transportation, and Federal Motor Carrier Safety Administration are aiding the investigation.

Tonya Alanez can be reached at tonya.alanez@globe.com. Follow her @talanez.