Colleges on the alert in low-tech ways, too

After the shootings last year at Virginia Tech and a February rampage at Northern Illinois University, colleges and universities nationwide are installing high-tech alert systems that beam emergency e-mails and voice messages to thousands of cellphones, pagers and personal computers to alert staff and students both on and off campus.

But in a bid to cover all their bases, they're also investing in decidedly more low-tech, Cold War-era alert tools: loudspeakers and sirens.

One Connecticut manufacturer says it has installed at least 100 loudspeaker-and-siren devices on college campuses -- more than half of those since the April 16, 2007, Virginia Tech shootings, in which a gunman killed 32 people and then himself. Another manufacturer, based in Illinois, says business has grown nearly fivefold since last April.

The reason? While cellphones, BlackBerrys and personal computers are ubiquitous, not everyone keeps them on hand all the ...