BLACKSBURG -- More than 700 subscribers say they did not receive messages during a test Wednesday of Virginia Tech's new emergency alert system.

The unannounced test was scheduled for 11 a.m., though computer problems forced Mark Owczarski, Tech's director of news and information, to make three attempts to record the voice message that was sent to cell and office phones across campus: "This is a test of the VT Alerts system. Thank you for your participation."

The voice message went out about 11:06 a.m. and started reaching subscribers about a minute later. Most subscribers received the test message within about 30 minutes, according to a tracking system Owczarski monitored through his computer. The 3N National Notification Network, a California mass communications company providing the service, said later Wednesday that messages were sent to all of the more than 18,000 subscribers within 18 minutes.

But as of 4 p.m. Wednesday, 711 subscribers said they did not receive any alert, according to a survey sent out after the test. Owczarski said 3N will study the issue over the next several days to figure out what might have gone wrong. It could have been problems with the system, with the cellular service providers or by subscribers' giving bad information.

"The bottom line is that's why we test," Owczarski said.

Tech plans to test the system each semester, though more tests may come sooner as the university and 3N troubleshoot Wednesday's problems.

The alert system debuted July 2, and more than half of the campus population of about 35,000 people have signed up for it. Tech contracted with 3N to message cellphones, conventional phones, e-mail and instant message accounts. According to the contract, Tech will pay 3N $200,000 over four years, though the service is free the first year and Tech can opt out of the contract early.

Subscribers can choose to be notified up to three ways and prioritize their choices. For example, subscribers who choose to be notified by a text message and an e-mail in that order they will receive a text message first. If they don't confirm they've received the text message, then they will receive an e-mail.

"The idea is to create a cascading effect," said Tech spokesman Larry Hincker.

It was more of a redundant effect for Hincker, however, as he received multiple messages on his cellphone during the test period.

"I confirmed receipt," he said, looking at his phone. "Why'd it ping me again?"

Data on Owczarski's computer during the test were also confusing, indicating that thousands of messages were being directed to "unreachable" destinations. But the number of delivered messages matched the total number of subscribers by about 11:30 a.m. Owczarski said 3N is also looking into what caused that problem.

"The good news is it's sending a ton of messages," said Mike Dame, director of university Web communication.

Text-message alerts have gained popularity on campuses across the country since the April 16 shootings at Tech. While there are no national statistics to track what percentage of people are signing up for the alerts, anecdotal evidence from media reports suggests that 50 percent is a high response rate for a large campus.

Students, faculty and staff at Roanoke College, Radford University and Hollins University received e-mails, and some received text messages, from their respective emergency notification systems during the past week with varying degrees of success.

About 1,500 people received notices when Roanoke College tested Maroon Alert, its optional emergency notification system, on Oct. 4.

There were no major failures during the testing, said Traci Crockett, a spokeswoman for the college. Some people apparently did not receive text messages, though they had signed up for them, she said. The university does not know how many people, if any, didn't receive the messages because no one has directly reported a complaint. The university sent out an all-campus e-mail Wednesday afternoon seeking feedback on whether the messages were successfully received.

A similar e-mail also was sent at Hollins, where the emergency warning system was tested Wednesday morning. Sirens blared around the campus, starting at 9:55 a.m. The sirens were followed by a test message broadcast over a loudspeaker. E-mails and text messages also were sent during the testing, said Jeff Hodges, a spokesman for the university.

Radford University ran the second full-scale test of its emergency notification system shortly after noon Tuesday. The system sends messages by telephone, e-mail and text.

During the first test, university spokesman Rob Tucker said there were "some very limited glitches with text messaging," but those glitches seem to have been resolved.

Additionally, Virginia Western Community College is hosting a meeting tonight as part of a statewide effort to examine campus safety at community colleges.

Tech was receiving bids from vendors for the alert service before April 16. While the system wasn't in place that day, Tech officials used other methods to get information to the campus community, such as e-mail alerts, announcements on its Web site, voicemail blasts and a siren and loudspeaker system that was tested earlier this week.

Tech received criticism after April 16, not for its technical ability to send out emergency messages but for not issuing a campuswide alert until 9:26 that morning -- more than two hours after the first round of shootings and less than 20 minutes before the second round. The state panel report was critical of what it saw as a system that was too slow in making such an urgent decision.

Hincker said the new alert system would be used judiciously but could be applicable during emergencies or bad weather that cancels classes. He has the authority to send messages through the new alert system along with Owczarski, Dame, Virginia Tech police Chief Wendell Flinchum and police Capt. Joey Albert. While one person rarely makes a decision to send out a campuswide alert, he or she can if the situation calls for it, Hincker said.

Staff writers Tim Thornton and Marquita Brown contributed to this report.