An incoming missile alert plunged residents of Hawaii into panic on Saturday morning before it was declared to be false.
Mobile phone users received a message saying: “Ballistic missile threat inbound to Hawaii. Seek immediate shelter. This is not a drill.”
State Governor David Ige apologised to Hawaiians, saying an employee had pressed the wrong button.
The US government announced there would be a full investigation.
An alert system is in place because of the potential proximity of Hawaii to North Korean missiles.
In December, the state tested its nuclear warning siren for the first time since the end of the Cold War.
In a tweet, the state’s Emergency Management Agency (EMA) said simply: “NO missile threat to Hawaii.”
Television and radio broadcasts across the state were also interrupted with a recorded emergency message: “Stay indoors!
“If you are outdoors seek immediate shelter in a building. Remain indoors well away from windows. If you are driving pull safely to the side of the road and seek shelter in a building while laying on the floor. We’ll announce when the threat has ended. This is not a drill!”
How did Hawaiians react?
AP describes reaction in the state as “full-blown panic” while according to the CNBC news channel, the alert “momentarily put recipients into a state of frenzy, with scores reportedly running for shelter”.
Matt Lopresti, a member of the Hawaiian House of Representatives, was at home when he received the alert on his mobile phone.
He described how he and his family had sought shelter in a bath tub.
“We got our children, grabbed our emergency supplies, put them in our most enclosed room in our house which is our bathroom,” he told local broadcaster KGMB.
“We put them in the bath tub, said our prayers, tried to find out what the hell was going on because we didn’t hear any alarms, any of the sirens.
“There’s not much else you can do in that situation. You know, we did what we could… and I am very angry right now because it shouldn’t be this easy to make such a big mistake.”
What is being done to prevent this happening again?
The US military confirmed no missile threat had been detected and the alert had been released in error.
Ajit Pai, chairman of the US Federal Communications Commission, announced the investigation on Twitter.
US President Donald Trump, who was in Florida at the time of the alert, was briefed on the false alert, the White House said.
Senator Mazie Hirono, a Democrat from Hawaii, tweeted: “Today’s alert was a false alarm. At a time of heightened tensions, we need to make sure all information released to the community is accurate. We need to get to the bottom of what happened and make sure it never happens again.”
Why was Hawaii already on edge?
North Korea’s missile and nuclear programme is seen as a growing threat to America. Hawaii is one of the US states closest to North Korea.
In September Pyongyang carried out its sixth nuclear test.
Last month, the Star-Advertiser reported that a missile launched from North Korea could strike Hawaii within 20 minutes of launch.
It turned out to be a false alarm triggered by an error in the earthquake warning system.