Janitor Gene Cole was cleaning bathrooms on the first floor of Virginia Tech's Norris Hall when a colleague told him there had been a shooting on campus.
We have to evacuate, the colleague said.
Cole headed for the second floor to look for a co-worker. As he walked down the hall, he saw a shape on the floor -- a student, covered in blood, his body jerking.
Then, from a nearby door, the gunman burst out. Gripping the gun in both hands, the man began firing.
"He's going to kill me! He's going to kill me!" Cole screamed as he spun and sprinted down the hall, bullets whizzing by his head.
He took the stairs two and three at a time, ran through an auditorium and into a neighboring building.
For Cole and others in Norris Hall, the nightmare began around 9:45am on Monday. Only later would the full chronology of the two-tier burst of terror became clear.
In the end, 33 people would be dead in what has become the US' deadliest shooting spree.
Just before 7:45am on Monday, Josh Ball shut the door to his fourth-floor West Ambler Johnston dorm room and headed toward the elevator. When he got to the double doors between the men's and woman's wings, he met a paramedic.
"You shouldn't go that way," the man said. "Just use the other stairs."
Outside, the 19-year-old saw a stretcher being loaded onto an ambulance. He assumed there had been a fight, and kept walking.
Ball had no idea that a fellow student had just unleashed hell.
He was not alone in not knowing.
It was not until 9:26am that the university sent out the first e-mail to students and faculty. The subject line read, "Shooting on campus."
"The university community is urged to be cautious and are asked to contact Virginia Tech Police if you observe anything suspicious or with information on the case," the message read.
About 20 minutes later, junior Alec Calhoun was in professor Liviu Librescu's solid mechanics class on the second floor of Norris when shots rang out from the German class next door.
Hilary Strollo was in her French class when the gunman entered the classroom. He moved methodically through the room, firing several bullets into each victim.
Strollo was shot in the abdomen, head and buttocks. She was hospitalized on Tuesday near Blacksburg.
Virginia Tech Police received the first emergency call from Norris at 9:45am. When they arrived, they found the front doors chained shut from the inside.
At 9:50am, a second e-mail went out warning students and staff to "stay put."
"A gunman is loose on campus," it read. "Stay in buildings until further notice. Stay away from all windows."
In the provost's office in neighboring Burruss Hall, administrative assistant Nadine Hughes, helpless to assist the wounded and dying next door, did the only thing she could think of: She began to pray.
But even then, much of the campus was oblivious to the carnage.
As police commando units were retaking Norris, Katrina Broas, a third-year student, chatted with classmates in her World Crops class in Litton-Reaves Hall. She heard sirens, but was not too concerned.
When class ended at 10:10am, students and faculty filed out to find the building locked down. They gathered in a conference room and watched the events unfolding on television.
A third e-mail, time stamped at 10:16am, announced that classes were canceled.
Not until 10:52am was the fourth e-mail issued, this one informing students of the shootings at Norris.