Six people were killed Wednesday after a driver crashed a vehicle into a construction zone near Baltimore, Maryland, police said.

The crash happened when a vehicle entered a work zone between temporary concrete walls and struck multiple construction workers in Woodlawn, state police said in a news release.

Maryland State Police responded to the crash around 12:40 p.m. Wednesday. The driver of the vehicle - whose identity has not been released - was taken to a trauma center for medical treatment.

Police indicated investigators believe a second vehicle may have been involved in the crash.

The construction area is located at the inner loop of Interstate 695 at Security Boulevard, police said. Some roads in the area were closed temporarily, but all roads were reopened by 6:45 p.m, a state police spokesperson told CNN.

The National Transportation Safety Board said it is sending investigators to work with the state police on the investigation.

Woodlawn is an unincorporated community about 8 miles northwest of Baltimore.