9:52 a.m.

The police clear the second floor of Norris Hall. Two tactical medics attached to the ERTs, one medic from VT Rescue and one from Blacksburg Rescue are allowed to enter to start their initial triage.

9:51 a.m.

Cho shoots himself in the head just as police reach the second floor. Investigators believe that the police shotgun blast alerted Cho to the arrival of the police. Cho’s shooting spree in Norris Hall lasted about 11 minutes. He fired 174 rounds, killed 30 people in Norris Hall plus himself and wounded 17.

9:50 a.m.

Using a shotgun, police shoot open the ordinary key lock of a fourth entrance to Norris Hall that goes to a machine shop and that could not be chained. The police hear gunshots as they enter the building. They immediately follow the sounds to the second floor.

Triage and rescue of victims begin.

A second email is sent by the administration to all Virginia Tech email addresses announcing that “A gunman is loose on campus. Stay in buildings until further notice. Stay away from all windows.” Loudspeakers broadcast a similar message.

Virginia Tech and Blacksburg police ERTs arrive at Norris Hall, including one paramedic with each team.

9:45 a.m.

The first police officers arrive at Norris Hall, a three-minute response time from their receipt of the call. Hearing shots, they pause briefly to check whether they are being fired upon, then rush to one entrance, then another and then a third but find all three chained shut. Attempts to shoot open the locks fail.

About 9:45 a.m.

The police inform the administration that there has been another shooting. Virginia Tech President Charles Steger hears sounds like gunshots and sees police running toward Norris Hall.

Back in 207 Norris Hall, the German class, two uninjured students and two injured students go to the door and hold it shut with their feet and hands, keeping their bodies away. Within two minutes, Cho returns. He beats on the door and opens it an inch and fires shots around the door handle, then gives up trying to get in.

Cho returns to room 211, the French class, and goes up one aisle and down another, shooting people again. Cho shoots Goddard again twice more.

A janitor sees Cho in the hall on the second floor loading his gun; he flees downstairs.

Cho tries to enter room 204 where engineering professor Liviu Librescu is teaching mechanics. Librescu braces his body against the door, yelling for students to head for the window. He is shot through the door. Students push out screens and jump or drop to grass or bushes below the window. Ten students escape this way. The next two students trying to escape are shot.

Cho returns again to room 206 and shoots more students.

9:42 a.m.

The first 911 call reporting shots fired reaches the VTPD. A message is sent to all county EMS units to staff and respond.

9:41 a.m.

A BPD dispatcher receives a call regarding the shooting in Norris Hall. The dispatcher initially has difficulty understanding the location of the shooting. Once identified as being on campus, the call is transferred to VTPD.

(The panel estimated that the shooting began at this time based on the time it took for the students and faculty in the room next door to recognize that the sounds being heard were gunshots, and then make the call to 911.)

9:40 until about 9:51 a.m.

Cho goes across the hall from room 206 and enters room 207, an elementary German class. He shoots instructor Christopher James Bishop and students near the front of the classroom, then starts down the aisle, shooting others. Cho leaves the classroom to go back into the hall.

Students in room 205, attending Haiyan Cheng’s class on issues in scientific computing, hear Cho’s gunshots. (Cheng was a graduate assistant substituting for the professor that day.) The students barricade the door and prevent Cho’s entry despite his firing at them through the door.

Meanwhile, in room 211, Jocelyne M. Couture-Nowak is teaching French. She and her class hear the shots, and she asks student Colin Goddard to call 911. A student tells Couture-Nowak to put the desk in front of the door, which is done, but Cho manages to nudge the door open. Cho walks down the rows of desks shooting people. Goddard is shot in the leg. Student Emily Haas picks up the cell phone Goddard dropped. She begs the police to hurry. Cho hears Haas and shoots her, grazing her twice in the head. She falls and plays dead, though keeping the phone cradled under her head and the line open. Cho says nothing when he enters the room or during the shooting. (Three students who pretend to be dead survive.)

9:31 - 9:48 a.m.

A VSP trooper arrives at the traffic stop of Thornhill and helps question him. A gunpowder residue field test is performed on him and the result is negative.

9:26 a.m.

Virginia Tech administration sends an email to campus staff, faculty and students informing them of the dormitory shootings.