Officials said the emergency alert about an incoming ballistic missile headed for Hawaii was a mistake.
People in Hawaii were sent into a panic Saturday morning when they got an emergency alert on their phones that said, "Ballistic missile threat inbound to Hawaii. Seek immediate shelter. This is not a drill."
Officials said quickly after that the alert went out by mistake and was a false alarm.
The Hawaii Emergency Management Agency tweeted, "NO missile threat to Hawaii."
Lt. Commander Joe Nawrocki of the North American Aerospace Defense Command, the agency in charge of providing aerospace warnings in North America, told BuzzFeed News, "There is no missile threat. We're trying to figure out where this came from or how this started. There is absolutely no incoming ballistic missile threat to Hawaii right now."
"My phone's blowing up right now," Nawrocki added.
Rep. Tulsi Gabbard and Sen. Brian Schatz, both of whom represent Hawaii, said on Twitter that alert was a false alarm.
"What happened today is totally inexcusable," Schatz later added. "The whole state was terrified. There needs to be tough and quick accountability and a fixed process."
The White House deputy press secretary released a statement saying President Donald Trump had been briefed on the incident.
"This was purely a state exercise," the statement said.
Trump was on the golf course at his swanky Florida resort, Mar-a-Lago, when the situation unfolded.
A Hawaii EMA spokesman also told BuzzFeed News that they were in the process of sending another message to cancel the initial alert.
"It was part of a drill that was going on," they said.
The second alert went out about 45 minutes later.
"There is no missile threat or danger to the State of Hawaii. Repeat. False alarm," the message said.
Twitter users were in a frenzy after the first alert was sent.
Hawaii began testing its nuclear warning system in December, CNN reported. It was the first time since the Cold War that Hawaii reinstituted the practice, and it comes as the US sees heightening tensions with North Korea, which has increased its nuclear aggression in recent months.