1:40 p.m. -- Armed with two pistols, gunman enters through the front entrance on the first floor of Western Psychiatric Institute and Clinic of UPMC, 3811 O'Hara St., Oakland, and starts shooting.
1:43 p.m. -- A person calls 911 from the second floor, reporting gunshots heard in a first-floor hallway.
1:45 p.m. -- Another person calls 911 to report that an active shooter was in the hallway.
1:48 p.m. -- Police report two people shot in the lobby.
1:56 p.m. -- The city's SWAT team is called.
1:58 p.m. -- UPMC hospitals in Oakland are put on what is called "bronze alert," meaning someone has a weapon. The alert requires employees to stay where they are and respond to the alert with their exact locations.
2:02 p.m. -- UPMC Presbyterian's emergency room tells dispatchers it needs more help.
2:08 p.m. -- A message sent to University of Pittsburgh employees says several people have been injured and that "lockdown [is] recommended until further notice."
2:13 p.m. -- Police report a male shooter dead in the hallway.
2:26 p.m. -- Police tell city schools to go to lockdown. A command post is set up at North Bouquet and O'Hara streets.
2:33 p.m. -- Additional police officers are called to the west side of the building.
2:41 p.m. -- Unverified reports indicate that a woman got a call from her sister, who said that a man was holding a gun to her head inside UPMC Presbyterian hospital. Police later said there was no hostage situation.
2:45 p.m. -- Command posts are set up at Pitt's Scaife Hall and inside the entrance of Western Psych along DeSoto Street.
2:48 p.m. -- SWAT begins clearing floors and sending civilians outside.
2:55 p.m. -- State, county and Port Authority police and South Hills SWAT teams are called in.
3:05 p.m. -- Police advise concerned family or friends to go to Petersen Events Center, where evacuees are being taken.
3:25 p.m. -- Bomb dogs are called to the bottom floor of Western Psych to inspect a suspicious item. The item is later cleared.
3:40 p.m. -- Police advise that Central Catholic and Oakland Catholic high schools and the School for the Blind can be released from lockdown.
3:50 p.m. -- A group of child patients is taken from Western Psych and driven to Petersen Events Center in an armored SWAT vehicle.
4 p.m. -- Two Port Authority buses for 60 people respond to the scene to transport evacuated people. Also, city police notify the Allegheny County Medical Examiner's office of two fatalities at WPIC. Medical examiners are told they will be called to the scene shortly.
4:05 p.m. -- SWAT teams continue the floor-by-floor search of the building.
4:40 p.m. -- Patients in secure wards are left in their rooms as SWAT teams sweep the building.
5:40 p.m. -- Police begin returning patients to the fourth and fifth floors of Western Psych from Petersen Events Center.
5:51 p.m. -- SWAT teams finish clearing the building. Police presence in the building begins to transition from SWAT teams to regular officers.