BLACKSBURG, Va., Dec. 7, 2011 -- In Hokie Nation, the phrase "April 16" is used in the same way most people speak of Sept. 11. It's shorthand for the worst mass shooting in American history.
It was mentioned a lot Thursday, as the midday killing of a Virginia Tech police officer, and a subsequent campus lockdown, instantly triggered thoughts of the massacre that took place here on April 16, 2007. Students were ordered to stay indoors and alerted to the dangers of a gunman on the loose, provoking fears of the worst.
"It was really hard, having kind of a throwback to April 16," said Ben Amos of Fairfax, Va., a member of the senior class.
But Amos, like most current Tech students, can only imagine what it was like when Seung Hui-Cho unleashed hell here in 2007, killing 32 other people before committing suicide.
Now 22, Amos was in high school at the time of the shootings. He was among the first crop of students to apply for admission to Virginia Tech in the aftermath of the bloodbath.
"I wasn't here [in 2007], but it did hit really close to home," said Jennifer Nicholson, a 19-year-old sophomore.
"Knowing that there was a gunman on the loose was just really scary," Nicholson told ABC News. "My mom was like, 'Text me every 10 minutes to make sure you're OK.'"
By late afternoon, officials held a news conference to announce the end of the alert and the campus slowly returned to life.
Students gave police and school officials praise for the quick work to lock down and alert the campus.
"Knowing that they responded so quickly and everything, it's just reassuring, especially to know that there are cops everywhere -- even in the big Humvees," said Nicholson.
University officials sent several alerts to students throughout the day, via text message, email and telephone calls. Several police agencies swarmed into this small college town.
"The response at Virginia Tech after April 16 is so quick and so thorough that I knew if [the shooter] was still on campus and still around, they would definitely have found him," Amos said.