Deputies responded to Columbia Machine Inc. on Bikle Road at approximately 2:30 p.m., where they found four victims, three of whom were pronounced dead at the scene, the Washington County Sheriff's Office said. The fourth remains critical.
The shooter fled the scene before law enforcement agencies arrived, and a description was released to responding units. The suspect vehicle was tracked down by Maryland State Police troopers near Maplesville Road and Mount Aetna Road, where they exchanged fire with the suspect.
Both a state police trooper and the suspect - whose name has not been released - were struck in the firefight and were transported to area hospitals for treatment.
Authorities said only that the responding trooper was shot in the shoulder while pursuing the suspect, then exchanged fire. The nature of their injuries and the status of the shooter was not immediately clear.
Multiple federal agencies, including the FBI and ATF responded to the scene and are assisting with the ongoing investigation.
A neighbor in a Facebook Live video reported seeing shots fired into a car around 3 p.m. at a business located at 12912 Bikle Road.
"They just shot up that f***ing car," said Harleigh Rae from behind the camera, adding a state trooper was struck.
There is no confirmed active threat to the community in relation to the shooting, a spokesperson for the sheriff's office said.
Thursday's shooting came a day after a 21-year-old Hagerstown resident was arrested for a similar incident outside the Valley Mall in Washington County.
More information was expected to be released.
Click here to follow Daily Voice Lancaster and receive free news updates.