A National Weather Service Tsunami Warning sent out this morning was a test. No warning is in effect, and there is no danger to the public.
Smartphone users may have received the alert as a notice on their phones. Once a user clicked in to the story, it became apparent this was only a test.
The alert was issued by NOAA, and was sent to users on the Gulf Coast and East Coast.
The National Weather Service issued the following statement: "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. We're currently looking into why the test message was communicated as an actual tsunami warning, and will provide more information as soon as we have it."
AccuWeather claims the warning was miscoded, causing it to be sent out by multiple outlets as a real warning. They add that the erroneous warning appeared on The Weather Channel and on the National Weather Service's own website as a real warning.
NWS and AccuWeather sent messages out via social media to alert the public that the warning was only intended to be a test and there was no threat.
AccuWeather also says this isn't the first time such a glitch has happened, having occurred some time around October 2014.