A Montgomery County, MD, police officer died hours after a shooting atop a Silver Spring parking garage Monday morning, and police are searching for those responsible.

Officer Thomas J. Bomba’s death at MedStar Washington Hospital Center was announced by interim police Chief Marcus Jones during a brief news conference Monday afternoon, WTOP reports.

Bomba, a 13-year veteran of the department, had called out on a radio about “disorderly subjects” in the parking garage, county police spokesman Tom Jordan said, and was found wounded by officers who arrived to assist. The officer reportedly confronted three subjects.