One man is dead and another is in critical condition after a gunman opened fire at an Alabama hospital before fatally shooting himself, police said.

Birmingham police Lt. Peter Williston said Wednesday police were called to UAB Highlands Hospital 6:55 p.m. Officers found two victims along with the gunman who had died of a self-inflicted gunshot, Williston said.

“The status on the victims: One victim is in stable condition,” Williston said. “Unfortunately, I have to report the second victim did not survive and was pronounced deceased during surgery,” he said.

Williston said investigators have a lot of information and evidence to sort through, “so we can try and determine what led to this tragic incident tonight.”

Authorities were unsure of the shooter’s relationship to the victims and whether the victims worked at the hospital, Capt. H.R. Watson of Birmingham Fire and Rescue told news reporters Wednesday night. He added that police “still have a lot to find out.”

Police had the scene secured and authorities issued an “all clear” alert about 7:45 p.m. after ordering students to shelter-in-place.

Al.com reported that paramedics were seen entering the building through the same-day surgery entrance and being taken to the second floor where the victims were believed to be located.

UAB tweeted late Wednesday that all surgeries scheduled for Thursday where the shooting occurred were being canceled.

UAB Highlands is a campus of UAB Hospital, which is part of the medical school at the University of Alabama at Birmingham.

(Associated Press, copyright 2018)