Oregon timeline: 10 dead in 10 minutes

10:30 a.m. Pacific time: Shots fired in Snyder Hall.

Officers responded almost immediately, requesting medical assistance and backup. Early reports indicated as many as 20 were wounded.

10:43 a.m.: Officers locate suspect, a male, on campus.

10:44 a.m.: Gunfire exchanged between officers and suspect. Thirty-five people reported inside building; campus is locked down.

10:49 a.m: Suspect confirmed dead

10:52 a.m.: First reports of death come in.

11:09 a.m.: All wounded victims go to hospitals. Campus is cleared.

11:14 a.m.: "All clear at Snyder Hall."

11:31 a.m.: More medical assistance arrives.

12:00 p.m. Buses arrive to take everyone on campus away. There were six buses and four ambulances, according to a reporter on the scene.

How it happened

Chris Harper Evans moved room-to-room and was targeting Christians specifically, Anastasia Boylan said to her father.

If they answered yes, he shot them in the head, according to the report.

In two instances, he shot the professors first.

Once, through the window and then entering the classroom, according to a witness account and then another time entering the classroom while unloading and telling the professor, "I've been wanting to do this for years," according to Boylan's testimony.

Witness accounts say hallways flooded with people in hysteria while other areas of the school stayed completely locked down.

State and federal officers both on the scene an hour later saying they had detained the suspect.

The school remained on lockdown while help arrived.

Wounded victims were treated with a "disaster-level response."

More information about the victims is expected Friday.

Read more witness testimony here.