A West York Borough police officer and a gunman were killed in a shooting Saturday morning that injured multiple staffers at UPMC Memorial Hospital in York County, Pennsylvania, the district attorney said.

Authorities described the shooting of a gunman who opened fire at a Pennsylvania hospital as “absolutely justified, beyond any and all doubt.”

Investigators are trying to determine why a man targeted a Pennsylvania hospital, taking workers inside the intensive care unit hostage and holding one staff member at gunpoint as her hands were bound by zip ties.