Updated 2:38 p.m. ET
As people along the East Coast, Gulf of Mexico and the Caribbean were preparing for their day around 8:30 a.m. ET, a smartphone push notification warned of a possible tsunami.
The threat, as it turned out, was nonexistent, though there is some disagreement over who is at fault for the erroneous message.
The National Weather Service tells NPR that it was a "test message" released by at least one private company as an official warning. In a statement, spokesperson Susan Buchanan said:
"The National Tsunami Warning Center of the National Weather Service issued a routine test message at approximately 8:30 am ET this morning. The test message was released by at least one private sector company as an official Tsunami Warning, resulting in widespread reports of tsunami warnings received via phones and other media across the East Coast, Gulf of Mexico, and the Caribbean."
The federal agency issued a tweet addressing the incident over an hour after the false warning was delivered.
The NWS would not elaborate on how widespread the warnings were but said the agency is looking into why the test message was communicated as an actual tsunami warning.
The NWS says neither the agency nor its National Tsunami Warning Center division was responsible for the false push notification, which they say was misinterpreted and issued as an official warning by "at least one" private company.
But AccuWeather, which sent out erroneous notifications, says that even though the word "test" was in the message header, NWS miscoded the message as a real warning rather than as a test.
Spokesperson Justin Roberti provided NPR with the following statement:
This morning AccuWeather passed on a National Weather Service Tsunami Warning that was intended by the NWS to be a test but was miscoded by the NWS as a real warning. AccuWeather has the most sophisticated system for passing on NWS tsunami warnings based on a complete computer scan of the codes used by the NWS. While the words "TEST" were in the header, the actual codes read by computers used coding for real warning, indicating it was a real warning.
"The NWS is the original source of the information and displayed it as a real warning," continued Roberti. "The responsibility is on the NWS to properly and consistently code the messages, for only they know if the message is correct or not."
The error comes weeks after a false ballistic missile alert in Hawaii declaring "THIS IS NOT A DRILL" advised residents and tourists to seek immediate shelter.
The alert issued by the Hawaii Emergency Management Agency was sent at 8:07 a.m local time. It took until 8:20 a.m. for the agency to post to its Twitter and Facebook accounts that there was no missile threat to Hawaii. It took the agency a full 38 minutes after it had sent the false alert to issue a correction through the emergency alert system.
The alert was issued because emergency worker believed there really was a missile threat, according to a preliminary investigation by the Federal Communications Commission. That employee, who had "confused real-life events and drills in the past" according to the FCC, was fired.