It took almost 40 minutes for an official statement to come out about the alert.
The incident prompted defense agencies including the Pentagon and the U.S. Pacific Command to issue the same statement, that they had "detected no ballistic missile threat to Hawaii."
Michael Kucharek, spokesman for the North American Aerospace Defense Command in Colorado Springs, Colorado, said NORAD and the U.S. Northern Command are still trying to verify what happened in Hawaii — but that "NORAD did not see anything that indicated any sort of threat to Hawaii."
NORAD is a U.S.-Canada joint command that conducts aerospace warning, aerospace control and maritime warning to defend North America.
The White House said President Donald Trump, who is in Florida, was briefed on the false alert. White House spokeswoman Lindsay Walters said it "was purely a state exercise."
Federal Communications Commission Chairman Ajit Pai said on social media the panel would launch an investigation.
The alert stirred panic for residents on the island and across social media.