People along America’s east coast were alerted to the threat of a tsunami on Tuesday morning – only to then be told that the warning message had been sent in error.

The National Weather Service issued a tsunami warning for Miami, Charleston and elsewhere at around 8.30am. The weather app Accuweather picked up on the message and sent out a mobile alert to subscribers.

“Tsunami warning in effect,” the alert said, adding the name of the recipient’s location. “Source: US National Weather Service”.

There was confusion on Tuesday morning over who exactly had bungled the message. The US Tsunami Warning Center was quick to absolve itself from blame:

The NWS New York office said it was investigating how a test message was sent out as a warning.

Meteorologist Hendricus Lulofs said there was a glitch during a routine test, which meant users of some mobile apps received what looked like an actual warning.

Last month Hawaii residents were told there was an incoming ballistic missile barreling towards the state. Hawaii authorities sent an emergency alert to cellphones which read: “Ballistic missile threat inbound to Hawaii. Seek immediate shelter. This is not a drill.”

It later emerged that a Hawaii state worker had sent out the alert after believing an internal drill was real. The man has since been fired.

The NWS and news organizations were quick to correct the error and assure people there was no incoming tsunami. But the proximity of the Hawaii missile message to the tsunami warning was not lost on internet users.