If you've the parent of a high school student, you're probably heard about lockdown drills.
A schoolwide alarm sounds, teachers lock their classroom doors and students hide under their desks, cracking jokes but hoping that this is really just practice. These exercises have become almost routine since the mass shooting at Columbine High School in Colorado in 1999.
Unfortunately, a system that works in a controlled high school setting may not work on a college campus.
With thousands of students scattered in dozens of buildings and dorms, eating in cafeterias, walking between classes, riding bikes or shuttle buses, playing Frisbee or commuting in their cars, how do you warn everyone that something is very, very wrong?
Critics have roasted Virginia Tech security officials for not sending out a campus alert Monday morning immediately after a gunman fatally shot two fellow students in a campus dorm. But even if they had sent out an immediate e-mail barrage, there was no assurance that enough of the school's 28,000 students and 1,300 faculty would have gotten the word in time to forestall the gunman's second, far deadlier rampage on the other side of the 2,600-acre campus.
That's one reason why the phones are ringing in the offices of Alertus Technologies, a five-year-old Rockville-based firm founded by a graduate business student who was disturbed by the lack of warnings after two sisters were killed by a tornado that struck the University of Maryland's College Park campus on Sept. 24, 2001.
At 5:10 p.m. that day, the National Weather Service issued a tornado warning for Prince George's County. Just 10 minutes later, the storm was ripping up the campus. "We realized that we really needed a more effective way to notify the campus community of an emergency," said Jason Volk, the firm's founder and CEO.
So he recruited engineering students who designed a simple and relatively inexpensive broadcast system that can beam an alert to a whole campus simultaneously.
Based on low-tech radio transmitters - although it can also use Wi-Fi or wired networks - the Alertus system flashes alerts to beacons mounted on walls in buildings all over campus.
Each beacon has a flashing strobe light, an audible alarm and a liquid crystal display for a written warning such as "Gunman at large - take cover." The beacons can also drive larger displays, such as plasma screens or outdoor marquees.
Volk says the system has been installed in a handful of buildings in College Park, where the business and engineering schools helped him raise the initial capital to get the system into production.
Other customers, Volk said, include Allegany County schools in Maryland, Mesa (Ariz.) Community College and the Berkeley County, W.Va., School District, with more in the pipeline - especially since Monday.
"Many campuses have indicated that they're not any more prepared than Virginia Tech was," Volk said. "The reality is that this is a critical issue for them right now."
Volk said his company can equip a large campus for less than $1 million - which he expects will be a major selling point.
There's little question that colleges will look hard at the high- and low-tech options available. The simplest, of course, would be a campuswide public address system.
Almost every elementary and secondary school in the country has one of these, but most colleges are so spread out that the cost would be prohibitive.
Almost all students and faculty have e-mail - but that can take hours to spread - with no way to reach students who are in class or just walking around campus. And it doesn't help maintenance, cafeteria and grounds workers who don't have e-mail.
Some schools, like the University of South Florida, have been trying to get students to sign up for cell phone alerts. But after two years, only 5,000 of the school's 45,000 students had enrolled in its Mobull Plus plan, according to the university's Web site. Of course, that was before the Virginia Tech attack.
There are also questions about the capacity of local cell towers to handle thousands of simultaneous warning calls or text messages, particularly in rural areas. Similar questions apply to users of extended pagers like the famed RIM BlackBerry - millions of whose users endured a 14-hour outage this week after a meltdown at the company's North American computer center in Canada.
Bottom line: No single technology can deliver timely warnings of natural or man-made danger to the thousands of students, faculty and staff who live on, commute to and roam the nation's college campuses. Security officers will have to develop creative combinations of communications channels - and hope that they never have to use them.