In yesterday morning's lecture on solid mechanics, all was quiet except for the sound of Professor Liviu Librescu's voice.
Then came the gunshots - in the classroom next door. In an instant, Virginia Tech's Norris Hall, a building dedicated to the science of engineering, was torn apart by the worst shooting rampage in modern U.S. history.
Junior Richard Mallalieu said he and about 20 classmates instantly dropped to the floor, ducking under and behind desks for what sounded like the first 10 shots.
"It wasn't like an automatic weapon, but it was a steady 'pow,' 'pow,' 'pow,' 'pow,'" Mallalieu, 23, said in a phone interview with The Sun. "We didn't know what to do at first."
Then the sound of the gunshots shifted. Coming closer.
Their next move became instantly clear: Get out.
Mallalieu said his professor held the door shut while students darted to the windows. Some climbed on desks, ledges and a radiator cover to pull down the screens and kick at the metal-framed glass, Mallalieu said. Three windows easily gave way and swung open on hinges as the gunshots got louder.
"It sounded like he was going out into the hallway," said Mallalieu, a civil engineering major from Luray, Va.
Once the windows for the second-floor classroom were open, Mallalieu and most of his classmates hung out of them and dropped about 10 feet to bushes and grass below, he said.
Some students ran to a nearby building. Others waited to help students who had been injured in the fall, Mallalieu said.
But then the sound of gunfire filled their classroom, sending all who had escaped toward nearby Patton Hall, he said.
Mallalieu said he never saw Librescu escape. "I don't think my teacher got out."
Librescu, a professor of engineering science and mechanics who was educated in Romania and is a U.S. citizen, could not be reached yesterday. As of 4 p.m., his wife had not been able to find him either.
"I am looking also. I know that he was shot, but I cannot find him," she said, panicked, in a phone interview. "How is it possible that a wife cannot know?"
She hung up before she could clearly state her full name.
Two hours earlier
All morning, news of the tragedy spread through e-mails, instant messages and phone calls. And though the mass killing in Norris Hall unfolded in mid-morning, the first shots had rung out about two hours earlier.
David Kramar, a 32-year-old graduate student, was working in his office at Major Williams Hall when the shootings started. He received an e-mail from campus officials that warned of shootings across campus at the West Ambler Johnston dorm and told students and faculty members to remain indoors.
Students began streaming into his building. "I had a couple of undergrads I teach who came in crying," he said. "People were terrified."
Soon, he heard shots from the direction of Norris Hall, which is nearby. "It was distinct gunshots. I don't know if it was police or the shooter himself."
About two hours later, when police allowed students and the faculty to leave their buildings, he went to a Blacksburg bar called the Rivermill for a beer to calm his nerves. From a phone there, he said, "Right now everything is on lockdown, the streets are empty. This stuff doesn't really happen in Blacksburg."
Freshman Katherine Runge, 18, of Towson lives in the huge Ambler Johnston dorm, which holds nearly 900 students. But her room is far from the location of the shootings, so she didn't hear anything yesterday morning.
In fact, about 8 a.m. - shortly after the shootings started - she left the dorm and went to breakfast at a nearby dining hall. After she returned to the dorm, a friend called, asking if she'd been told to stay in her room.
"I just thought she was joking around, trying to scare me," the Towson High grad said. She realized the danger was real when she received an e-mail at 9:26 a.m. from school officials warning that a shooting had occurred on the west side of the dorm.
"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 e-mail read. At 9:50, she received another, more ominous, message. It read: "A gunman is loose on campus. Stay in buildings until further notice. Stay away from all windows."
As police cars and ambulances rushed to the dorm, she called her parents to say she was unharmed.
"Everyone was scared," she said. "Cops were running around outside with huge rifles."
'We were in shock'
Freshman Claire Hach, a graduate of Notre Dame Prep in Towson, was about to leave her class in Wallace Hall when a school official grabbed her and told her to immediately head to a computer lab in the basement. It was then she saw the computer printouts taped to the door.
The 19-year-old business management major and another student calmly walked to the computer lab. They still did not know what was happening at Norris Hall.
No one knew what the signs meant, she said. They had heard about a dorm shooting, "but we thought it was a freak accident," said Hach, whose sister Ashley is a junior at Virginia Tech.
"In the beginning we weren't taking it seriously," she said. But then the news Web sites relayed what was happening. "As we kept hearing that people were killed we were in shock."
Police on the scene
Brett Mastropieri, 23, a senior mechanical engineering major from Monkton, was in class in McBryde Hall, near Norris Hall, at the time of the shooting. He said a distant booming caught the attention of people in class, but many thought it was construction.
"Toward the end of class a bunch of students got the e-mails and text messages [about the shootings]," said the graduate of Loyola Blakefield High School.
As they left the building, they were told to get away from the buildings. "We watched the police as they surrounded the buildings," he said. "We didn't hear any shooting after that."
Sun reporters Chris Emery, Brent Jones and Gadi Dechter contributed to this article.