Electronic devices sounded off across the United States on Wednesday afternoon as the Federal Emergency Management Agency conducted an emergency alert test.
The tone sounded at 2:18 p.m. Eastern Daylight Time. The subject read: "Presidential Alert" and text read: "THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed."
It is the first test of the national wireless emergency system by FEMA. The message was broadcast on cell towers for 30 minutes. Some people got the alert multiple times. Others didn't get it at all.
FEMA estimated about 225 million electronic devices, or about 75% of all mobile phones in the country, would receive the alert. It hasn't said yet whether the test went well.
The system test is for a high-level "presidential" alert that would be used only in a nationwide emergency. The goal is to have phones get the alert at the same time.
The wireless alert system launched in 2012. While users can opt out of messages on missing children and natural disasters, they can't opt out of the presidential alerts, which are issued at the direction of the White House and activated by FEMA.
FEMA officials said the administration can send such an alert only for national emergencies or if the public were in peril, rules outlined in a 2006 law, and they say it can't be used for any sort of personal message from the president.
A group of New Yorkers filed a lawsuit in federal court in New York arguing that they should not be compelled to receive the alerts under their right to free speech.