UPMC announced this morning via a Facebook post that it has closed Memorial Hospital in West Manchester Township to visitors in the wake of a hostage incident Saturday that left one police officer dead, two injured and several staff members injured. The health care system did not say when visitors to patients would once again be welcome.

Officials are investigating a possible motive that led to a man entering the UPMC Memorial Hospital ICU where several staff members were shot and taken hostage on Saturday. ABC News reports that Diogenes Archangel-Ortiz,

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