Authorities say a shooter entered UPMC Memorial Hospital's ICU and took staff members hostage before he was killed by police in a shootout.

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

A gunman who held medical staff hostage before killing a police officer and wounding five others at a hospital in south-central Pennsylvania Saturday is believed to have visited the facility in the days leading up to the incident,