Dec. 8, 2011 -- When a Virginia Tech student named Seung-Hui Cho opened fire on his schoolmates and killed 32 people and himself in 2007, the university was caught unprepared. It had an emergency warning system, but it did not send out the first tentative warning until two hours after the shootings began.
The warnings today were fast and numerous, four of them in the first hour after a campus police officer was reported shot during a traffic stop. Under a 1990 federal law known as the Clery Act, universities are required to provide prompt information about dangers on campus.
"From VT Alerts (12:37 p.m.): Gun shots reported - Coliseum Parking lot. Stay Inside. Secure doors. Emergency personnel responding. Call 911 for help," said the first message on the Virginia Tech website. Ten minutes later: "Suspect described as white male, gray sweat pants, gray hat w/neon green brim, maroon hoodie and backpack. On foot towards McComas. Call 911."
Virginia Tech in Blacksburg, like many other colleges, now has a system that sends alerts to message boards in classrooms and dorms, and text messages to cellphones and other digital devices that students, staff and faculty members have registered with the system. It also sends them out on Twitter, its Facebook page and online video.
"The communications systems we have today did not exist on April 16, 2007," said university president Charles Steger. The school said six alerts went out, all told, including one saying the crisis was over and it was safe to go outside.
The school sent alerts about every 30 minutes, regardless of whether they had any new information, university spokesman Mark Owczarski said.
"We deployed them all, and we deployed them immediately to get the word out," he said.
Virginia Tech says it has 6,800 employees at its campus in Blacksburg, Va. There are 9,000 students who live in campus dorms, though fewer would have been there today because classes were not in session, said administrators.
Some of the messages, the school said, were meant to ease the inevitable confusion that followed the shootings, such as reports of more gunfire, and rumors that another school nearby, Radford College, was on lockdown, too.
This was one of several messages after the initial report:
"Update: Shooter's status remains unknown; visitors advised to stay away from campus.
"(Posted: 2:20 p.m.) Numerous reports have been made recently of sounds identified as gunshots and suspicious activity on campus. These recent reports have been investigated and are unfounded. The suspect's status remains unknown. Several law enforcement agencies are on scene to assist. Please stay where you are and secure your surroundings."
By coincidence, today's shootings happened just as Virginia Tech managers were appealing a $55,000 fine levied by the U.S. Department of Education after the 2007 tragedy. The department said the school violated the Clery Act because of its slow response that day.
Did today's warnings work?
Brett Hockersmith, a 22-year-old senior whose brother was a Virginia Tech student in 2007, said he first saw the alerts on electronic message boards while he was studying for finals with other students. He said people immediately started looking for more information online and followed the directives by remaining indoors.
Although he has seen false alarms from the warning system, Hockersmith said that he took today's alerts seriously.
"The other [alert] over the summer said there [was] a reported shooting," Hockersmith said, referring to an unfounded alert in August that there was an armed man on campus. "[But] this one said there was a confirmed shooting, so I took it seriously."
ABC News' Gillian Mohney contributed reporting for this story, with additional information from the Associated Press.