COLUMBIA, Missouri -- The gun massacre on the campus of Virginia Tech last year that left 33 people dead sent colleges across the United States scrambling to improve how they get alerts to students during crises on campus. One solution: Text messages sent to cell phones.
But while hundreds of campuses have adopted text alerts, most students are not embracing the system - even in an age when they consider their mobile phones indispensable.
Omnilert, a Northern Virginia company that provides an emergency alert system called e2Campus to more than 500 U.S. campuses, reports an average enrollment rate among students, faculty and staff of just 39 percent.
Another industry leader, Blackboard Connect, reports even lower participation - 28 percent for the 300 campuses that use its Connect-Ed emergency alerts.
Across the country, colleges "are really struggling with how to get the enrollment numbers up," said Steven Healey, Princeton University's public safety director and an expert on campus security.
Other companies who provide the services declined to release detailed enrollment figures to The Associated Press.
The University of Missouri's Columbia campus tried a giveaway - students who signed up for the alerts were entered in a drawing for an iPod Nano - in hopes of improving its rate. Just 15 percent of the roughly 28,000 students have requested text message alerts or cell-phone calls during emergencies.
The low participation, and fresh concern following the deaths of five Northern Illinois University students by a gunman earlier this month, led University of Missouri president Gary Forsee to issue a new plea.
"Alert systems are only as effective as our ability to make contact with you," he wrote in an e-mail to each of the system's four campuses, encouraging students to enroll immediately.
Even at Virginia Tech, where a gunman killed 32 people and himself last April, four in 10 students still have not signed up for emergency text alerts. The campus also employs other alert methods, including e-mails and online instant messages.
Campus safety experts point to several factors to explain the lack of interest among students, including feelings of invincibility and reluctance to give out personal information.
Others hesitate to pay the fees - generally a matter of pennies - that some cell phone providers charge to send and receive texts. Colleges generally pay $1 to $4 per enrolled student to the companies that set up the alerts.
"It will take time to earn their trust," said Bryan Crum, an Omnilert spokesman. "That day will come once they see how it can personally benefit them - and once they realize we're not out there to sell their personal information, and that 10-cent charges once or twice a semester is worth the price of personal safety."
Safety experts emphasize that text alerts should be just one part of comprehensive notification systems that can include sirens, loudspeakers, security cameras, Web site announcements and more.
On the day of the shooting, Northern Illinois sent out e-mail and voice mail alerts. The school does not participate in text message alerts.
"You don't necessarily have to reach every person to get saturation," said S. Daniel Carter of Security on Campus, a Pennsylvania nonprofit that pushes for safer college campuses.
"If you reach a quarter of the people on campus, they're going to start spreading the word. They're not going to start saying, 'Oh, that's interesting,' and close their phone," he said.
As campus shootings continue to make headlines, student participation may increase, Healey said. At Princeton, 90 percent of first-year students are enrolled, compared with an overall rate of 64 percent for all undergraduates.
The school's application for admission now asks potential students to provide their cell phone numbers in case of emergency.
"These kids lived through Virginia Tech," he said, referring to the freshmen. "They were high school seniors about to head off to college."