Many Florida residents woke up to a screeching alarm around 4:45 a.m. on Thursday, after an early morning test of the emergency alert system blared from their cellphones.
The Florida Division of Emergency Management, which coordinates and manages alert systems for emergencies such as hurricanes and other disasters, apologized for the notifications in a statement.
“The division understands that unexpected 4:45 a.m. wake-up calls are frustrating and would like to apologize for the early morning text,” Alecia Collins, a spokeswoman for the agency, said in an email.
“Each month, we test emergency alerts on a variety of platforms, including radio, television and text alerts,” she said. “This particular alert was supposed to be on TV, and not disturb anyone already sleeping.”
The alerts jolted some Floridians out of bed on Thursday, and in homes with multiple cellphones, the sounds created an early morning cacophony.
On social media, Floridians complained about the alert and shared screenshots of their phone screens with the notification, which said: “This is a TEST of the Emergency Alert System. No action required.”
Officials in St. Lucie County in southeastern Florida said on Twitter that the alert was sent to “every wireless subscriber” in the state. There were more than 22.8 million wireless subscribers in Florida in 2021, according to the Federal Communications Commission.
The test on Thursday morning was supposed to be for television alerts, which are usually broadcast early in the morning when the fewest number of people are watching to minimize disruptions, Ms. Collins said.
She said that the emergency management agency “was taking the appropriate action to remove the company responsible for submitting the alert this morning.”
Ms. Collins said that a software company that the state contracts with, Everbridge, sent the wrong technical specifications for the alert. Everbridge did not immediately respond to a request for comment on Thursday.
Gov. Ron DeSantis said on Twitter that he had ordered the agency to “bring swift accountability for the test of the emergency alert system in the wee hours of the morning.”
“This was a completely inappropriate use of this system,” he added.
The blaring alarms prompted some on social media to explain how to stop getting these notifications, but Florida’s emergency management division urged people not to turn them off, saying such alerts are important for public safety.
The National Weather Service office in Tampa Bay also acknowledged that the alerts were “inconvenient,” but said on Twitter that it “strongly” discouraged people from disabling the alerts because it could cause them to miss weather warnings “that may mean the difference between life and death.”
For more than a decade, the United States has sent emergency alerts to mobile phones, while countries such as Britain are only just adopting the technology.
The first nationwide test of Britain’s new system is scheduled for Sunday and there has been an extensive national campaign to make sure people are prepared for the test and future alerts, which could be sent out for severe weather, including flooding and fires.
The mistake in Florida did not represent the first time that an emergency alert test for cellphones went awry.
In January 2018, people in Hawaii received a false alert warning of an incoming ballistic missile and it took about 38 minutes for the state to send an alert that said the first one was an error. The false alert was sent by a worker with a long history of poor performance who had thought that the state faced an actual threat, said F.C.C. and Hawaii officials.