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: