Authorities are asking witnesses to come forward as they investigate last week’s bus crash on southbound Interstate 95 in Stafford County, Virginia that killed five people and left 44 people injured.

Virginia State Police said their initial investigation found that on May 29 around 2:35 a.m., a bus was that heading to Charlotte, North Carolina, from New York City when failed to slow down as it approached traffic that was slowing on southbound I-95 due to a work zone.

The bus, carrying 34 people, hit six vehicles, including a Chevrolet Suburban, which then hit an Acura SUV.

NTSB said a high rate of speed played a role in the crash.

Four of the fatalities occurred inside the Acura: Dmitri and Ecaterina Doncev, 45 and 44 respectively, and their children Emily and Mark. The family were from Greenfield, Massachusetts. The remaining victim was Priscilla R. Mafalda, 25, of Worcester, Massachusetts, who was inside the Chevrolet.

The bus driver in the crash was identified by Virginia State Police as Jing S. Dong, 48, of Staten Island. Authorities said he was charged with five counts of involuntary manslaughter and one misdemeanor count of reckless driving.

Anyone with information or video of the crash is asked to contact authorities at 804-750-8778.

The investigation is ongoing, as officials from NTSB said that they will release a preliminary report before June 30.