LEWISBERRY, Pa. (AP) — Three construction workers on a maintenance project along a Pennsylvania interstate were struck and killed by a truck early Wednesday, state police said.

Investigators said a 24-year-old man was driving a large box truck at about 3:25 a.m. when it struck a construction vehicle in a work zone, then hit the three workers on the shoulder.

The fatal crash occurred in the southbound portion of Interstate 83, about 8 miles (13 kilometers) south of Harrisburg.

State police have not disclosed the victims’ names, but Pennsylvania Department of Transportation spokesman Dave Thompson said they worked for an agency contractor.

“Right now we’re just gathering information,” Thompson said. “We’re obviously very shaken by this event.”

The crew was sealing highway cracks at the time, Thompson said.

A Transportation Department news release issued a week ago said the overnight work involved lane closures and was being performed by CriLon Corp. of Somerset. A phone message seeking comment was left early Wednesday at CriLon offices.

The York County Coroner’s Office confirmed the location of the deaths but offered no other details.