Since 9/11, some security experts have pushed the idea that peer-to-peer alert systems that rely on openness and the crowd can save lives, particularly when centralized communications and decision-making break down.

That argument is back in force following Monday's mass slayings of 32 people at Virginia Tech.

As the carnage unfolded, eyewitnesses IM'd terrifying firsthand accounts to their friends, some of which appeared on blogs and MySpace within minutes of the shootings. Yet students complained that the first official word they heard about a killer on campus came a full two hours after two students were shot to death in a nearby dorm, just as their suspected attacker opened fire again in an academic building on the other side of campus.

"The kids demonstrated that in a disaster, we will use whatever tools are at hand to communicate," says W. David Stephenson, who has been advocating for innovative and collaborative disaster tools since the World Trade Center terror attack. "It adds up to the stark reality that the first incident should have resulted in an immediate lockdown, and the second round of shooting – unless there's something that hasn't been reported yet – should never have happened."

As the nation comes to grips with the worst mass shooting in modern U.S. history, debate will turn inevitably to gun control, youth alienation and video-game violence. Emergency responders, meanwhile, will be asking tough questions about tactics and technology.

Why, given the ubiquity of SMS-enabled cell phones and the growing popularity of social networking and communication tools like Twitter and dodgeball.com, did it take so long for news to reach students that class had been canceled and that students should stay in their dorm rooms?

Next-generation emergency-alert systems have sprouted up across the country, aiming to bring better information and decision-making to disaster scenes. New York City's planned 911 system would allow callers to send in cell-phone pictures and videos; Portland, Oregon's Connect & Protect system combines ad-hoc and centralized information sharing; and SquareLoop's technology enables emergency messages to be sent to any phone in a given geographic area, according to Stephenson.

In its own slow way, the federal government has responded to lessons learned from Sept. 11 and Hurricane Katrina and in the fall, Congress passed the Safe Port Act that lassos cell-phone companies into becoming a nationwide SMS alert system.

The system is one of many relying on the Common Alerting Protocol, or Cap, that allows officials to write an alert once in a specially designed format and then send it out through multiple distribution technologies.

The Federal Communications Commission will begin the federal rulemaking process on the new network some time in the fall, meaning the system won't be rolled out until sometime in 2008 at the earliest.

Some colleges are also exploring new emergency alert methods.

The University of California at Berkeley relies on tried-and-true alert-warning horns to broadcast an emergency, but recently launched a beta test of a wikilike technology called People Locator that can be used during a disaster as a centralized bulletin board.

Anyone can leave a message or post information, while those with UC-Berkeley online credentials can leave an official message, such as their status after an earthquake. Emergency officials can mine the tool for relevant information, such as where students suspected to be exposed to radiation now are.

The issue is only partly about technology, experts say. Regardless of the system used, effective response often boils down to tough human decisions about when to use the system, and how.

Virginia Tech officials have defended their actions, saying they had reason to believe the shooter had left the campus, so they saw no reason to cancel classes for the 25,000 full-time students.

"It's so tricky to talk about at this point – there's so much we don't know, but in general the most common mode of failure (in notification technology) is the failure to use it in a timely fashion," says Art Botterell, a longtime specialist in disaster and technology who is sympathetic to the officials' plight. "There is always the question of what kind of capability you have, but the part of the process that is hardest is the decision-making."

Some wonder whether a distributed disaster-communication system – using tools such as a disaster-ready wiki, presence-registering networks and a 911 service that shares information two ways – might have performed better.

"I think there is a generational gap between the way the announcement was broadcast and the way 20-year-old students communicate," says Eric Bonabeau, a network analysis expert and CEO of Icosystem, who argues that Virginia Tech should have been more attuned to college students' habits.

"We are working on understanding how the emergence of smart swarms can be shaped in crisis situations by giving people tools to communicate such as wikis and ad-hoc alert networks – and encouraging them to do so rather than limiting communications, which seems to be any administration's first instinct. The information might be redundant but is often of surprisingly good quality thanks to self- and mutual-policing mechanisms."

Botterell, who is on a committee that is helping the FCC craft the rules, supports the new system and disaster-response innovations in general, but cautions that no technology is a magic wand.

"If you look at what we know about how human beings make decisions, you can't just give them one message – it's not like command and control," Botterell said. "People need a web of corroboration, and we are seeding that word-of-mouth mesh because ultimately that's where decisions are made.

"People look at the eyes of their peers and that's where decisions are made."

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