CNN —

A tragic incident unfolded at UPMC Memorial Hospital in Pennsylvania when a gunman took the intensive care unit staff hostage, resulting in the death of a police officer and injuries to five others. The assailant believed that inadequate efforts were made to save his wife, who had been on life support due to a terminal illness, according to law enforcement officials involved in the ongoing investigation.

Diogenes Archangel-Ortiz, aged 49, had been escorted out of the hospital the night before the attack after exhibiting anger and emotional distress upon learning that no further treatment options were available for his wife. It remains unclear if she has since passed away.

During a news conference on Saturday, York County District Attorney Tim Barker revealed that Archangel-Ortiz had visited the ICU earlier that week for a medical matter related to another patient. However, additional details have not been disclosed as of Monday.

On Saturday morning, Archangel-Ortiz returned to the hospital armed with a firearm, zip ties, and duct tape, taking several staff members hostage before dying in a shootout with law enforcement.

The shooter opened fire during the ordeal, injuring three officers and fatally wounding one—identified as Officer Andrew Duarte from the West York Borough Police Department.

According to the York County Coroner’s Office, the 30-year-old officer’s death was classified as a homicide. Reports indicate that Officer Duarte succumbed to gunshot wounds to his torso.

A memorial service honoring Duarte’s life is scheduled for Friday, February 28, at Living Word Community Church in Red Lion, Pennsylvania. His obituary states that he is survived by his parents, girlfriend, and other family members.

Among the injured were an ICU doctor, a nurse, and a custodian, all of whom sustained gunshot wounds. Additionally, a fourth staff member was hurt during the incident. Fortunately, by Sunday, they were reported as “medically stable and progressing” in their recovery, according to a hospital statement.

Thankfully, no patients were harmed during the attack, confirmed Susan Manko, a spokesperson for UPMC Memorial.

The investigation is being led by the Pennsylvania State Police with support from the York County District Attorney’s Office.

A spokesperson for the state police stated that further details will not be released until the investigation concludes, but assured that all aspects of the incident will be thoroughly examined.

CNN’s Karina Tsui contributed to this report.