The message that lit up cellphones and in-boxes across the campus of Virginia Tech University at 12:37 p.m. Thursday was terrifying in its brevity.
"Gun shots reported—Coliseum Parking lot. Stay inside. Secure doors. Emergency personnel responding. Call 911 for help."
These are fraught words for any community, but at Virginia Tech, they struck to the core. Officials still grapple publicly with fallout from the nation's deadliest campus shootings in 2007, when Seung-Hui Cho shot and killed 32 people before killing himself. Criticized then—and now—for taking too long to warn the campus that day, administrators and law-enforcement officials wasted no time on Thursday following reports that a university police officer had been fatally shot during a routine traffic stop by a gunman who then fled on foot.
The alerts came quickly and efficiently. And as state police officers, SWAT teams, and canine units swarmed the campus, Virginia Tech officials confronted an unfathomable situation: They had tested their new emergency-notification system before, but not with a threat quite like this. Federal law, for starters, now requires institutions to develop emergency-response plans and test them each year. But this wasn't just a test. They had to get it right.
For four hours—from that first, jarring alert until the police gave the all-clear around 4:30 p.m.—students, faculty, and staff scrambled to take cover. At first they knew only that a shooting had occurred on the campus. Then they learned that it was a police officer who had been shot. Within 90 minutes, they knew that the officer, later identified as Deriek W. Crouse, had died, and that a second person had been found dead not far away.
By 4:30 p.m., when news finally came that the authorities had lifted the alert, at least six notifications had gone out to the university community. The Virginia State Police, which had assumed control of the investigation early on, deemed the campus safe.
"There is no longer an active threat," the final alert stated. "Resume normal activities."
The announcement brought relief, mixed with sadness over the loss of life. But Thursday's events unfolded with eerie timing: Earlier that day, at a hearing in Washington, the university appealed a $55,000 fine the Education Department levied against it last spring for violating a federal campus crime-reporting law in its handling of the 2007 rampage. Federal officials had determined that Virginia Tech's warning to students and employees the morning of April 16, 2007, was too late and too vague, and concluded that it violated the federal Clery Act.
On that day, the university sent its first campuswide e-mail more than two hours after the campus police received an emergency call about shootings in a residence hall. The e-mail stated that a "shooting incident" had occurred, and that "the university community is urged to be cautious." A second campuswide e-mail 19 minutes later contained instructions to "please stay put," and referred to "a gunman loose on campus."
(Virginia Tech officials have contested the department's findings, saying that they acted in accordance with law at the time. In 2008, federal law changed to require institutions to issue immediate emergency notifications when active threats to the health or safety of students and employees emerge.)
Still, in the years since the mass shootings took place, the university has made major changes. It created the emergency-notification system that was in effect on Thursday, hired additional police officers—it now has more than 50, plus 20 security guards, officials said—and created "threat assessment" groups to assess students and employees who might be at risk of committing crimes.
Thursday was a test like no other. And by all accounts, it worked. By early evening, the university's president, Charles W. Steger, told reporters that all the safety measures and communications systems the university has since put in place were a success. He noted that university police first received word that an officer had been harmed shortly before 12:30 p.m.; less than 10 minutes later, university police issued the first alert.
"Sometimes technology doesn't cooperate with you," Mr. Steger said. "But today it worked."
'I Should Really Get Indoors'
As news of the shooting broke, the campus shifted rapidly into lockdown mode. For Peter Smith, a fifth-year senior, taking cover quickly proved to be a challenge. A friend had just dropped him off on campus when he received the first VT Alert text message of a shooting on campus. Recalling several previous incidents in recent years when other alerts were revealed to be false alarms, he continued on to the library to study for an exam.
But the library was locked. He tried two nearby academic buildings—they were locked, too. That's when Mr. Smith received a third text alert. It stated that a police officer had been shot.
It struck Mr. Smith that this was not a false alarm: "I should really get indoors right now," he recalled in an interview with The Chronicle. As he looked around the campus, he saw no other people. He found it "terrifying." After walking around one of the locked academic buildings, he was able to duck into an open side door just minutes before a security officer locked it. Then, as he took refuge with several dozen other people in an enclosed bridge between that building and the adjacent library, he realized how scared he was.
"I was shaking uncontrollably," he said. He eventually left the campus after authorities said it was OK to do so later that afternoon.
Allison V. Rizzetta was already inside the Squires Student Center attending a meeting when the news came. People sprinted down the hallway toward the windows. Around 2 p.m., more than an hour after the first alert, a loudspeaker instructed everyone inside the building to go inside a nearby auditorium.
"That was the scariest part, because we didn't know why we had to go into the auditorium," said Ms. Rizzetta, an environmental-resource management major. "I thought maybe they were moving us into the auditorium because the shooter was in the building."
About 400 people gathered in the auditorium. Some were visibly upset, she said; others followed the latest news on laptop computers, or made phone calls to friends and relatives. As updates rolled in from the university, she said, the anxiety in the room quieted.
Virginia Tech has had several other brushes with crime in recent years that have tested the university community's response. Just last August, officials ordered students and staff to stay inside and lock their doors after receiving reports that an armed man was on the campus. Hours later, they lifted the alert after learning that the initial reports, from three youths in a summer camp, were unfounded.
While some, like Mr. Smith, viewed such incidents as false alarms, others consider them critical exercises in how to behave during an emergency.
"The students recognize when they're getting emergency alerts that they need to pay attention to them," says Dolores Stafford, a former chief of police at George Washington University who led an investigation of Virginia Tech's policies after the 2007 shootings and now consults on campus security issues. And most universities, she added, have adopted communications systems that allow officials to send out immediate alerts across multiple platforms.
Ms. Stafford was present at the hearing in Washington on Thursday morning to testify on Virginia Tech's behalf in its appeal of the Clery Act violation. The hearing wrapped up just a few minutes before noon. She left, grabbed some lunch, and saw the news flashing across the television screen at the restaurant.
"Oh no," she recalls thinking. "Not again."
Jennifer Gonzalez, Sara Lipka, Beckie Supiano, and Robin Wilson contributed to this article.