Maureen Dyke was sound asleep at 1:40 a.m. Monday when her iPhone buzzed to life.
"It sounded kind of like a fire alarm," said Dyke, 28, of Oldsmar.
The message read: "An AMBER alert has been issued in your area, please check local media."
Dyke was among thousands of residents throughout Florida who received the message as part of the Commercial Mobile Alert System, a new program used to distribute emergency alerts via text message nationwide.
The system, operated by the Federal Emergency Management Agency, was launched in April. This month, the National Center for Missing & Exploited Children signed up.
Monday's Amber Alert, issued when authorities in Collier County feared that a child had been abducted, was the first one in Florida in 2013.
"These are designed to alert people who are on the go," said Charles McCobb, manager of the FEMA program that operates the alert system. "This provides a much more modern method of alerting people on the go."
The system can also send out alerts for severe weather or national emergencies.
The alerts, free of charge, are distributed by about 140 cellphone companies nationwide, including Verizon, AT&T, Sprint and T-Mobile, McCobb said.
The number of Florida residents who received the alert early Monday ranged in the thousands, McCobb said, but an exact total is not available because of the number of cellphone companies involved.
Before the new system, cellphone users had to sign up to receive Amber Alerts, sent to subscribers based on the ZIP code in which they live. With the new alert system, officials said, most smart phones are automatically signed up, reaching more people.
Except for national emergencies, customers can unsubscribe from the alerts by calling their service provider, McCobb said.
The alerts are sent out via cellphone towers, either county- or statewide. So tourists visiting Florida, regardless of where they came from, would have received Monday's alert, officials said.
The Amber Alert early Monday was released after a 2-year-old girl in Immokalee disappeared. She was found safe hours later.
In Florida, Amber (or America's Missing: Broadcast Emergency Response) Alerts are issued by the state's Department of Law Enforcement using the FEMA program. To send an Amber Alert through the new text system, the FDLE can contact the National Center for Missing & Exploited Children. The FDLE also alerts residents through email and social media.
Across the Tampa Bay area, several residents were awakened by an alarmlike sound from their cellphones.
Ed Offner of Tampa thought his car alarm had gone off. But after realizing it was an Amber Alert, Offner said, "I wasn't annoyed at all. I have two kids."
In St. Petersburg, Sabe Maysonet was awakened by the loud alarm on his BlackBerry. He read the text message, which urged him to check "local media" for details, but Maysonet said he went back to sleep.
"I was expecting a little more detail," Maysonet said. "A follow-up maybe. It was just vague."
The text messages are limited to 90 characters.
"We need to keep it short," said Bob Hoever, director of special programs at the National Center for Missing & Exploited Children. "The whole purpose is to tell people, 'Hey, we have a problem here' and direct them to the media."
But Maysonet said the alerts are "good to have," adding that he won't be calling to unsubscribe.
"I don't see how it can be negative for anyone," he said.
Laura C. Morel can be reached at email@example.com or (813) 226-3386.