President Trump's first public remarks Saturday after a false alert warning Hawaiians of an approaching ballistic missile threat was not to comfort people whose nerves were on edge, or assurance that such an incident will never happen again. Instead, Mr. Trump tweeted about "fake news" promoting "mentally deranged" Michael Wolff, author of "Fire and Fury: Inside Donald Trump's White House" and the 2016 election.

So much Fake News is being reported. They don’t even try to get it right, or correct it when they are wrong. They promote the Fake Book of a mentally deranged author, who knowingly writes false information. The Mainstream Media is crazed that WE won the election! — Donald J. Trump (@realDonaldTrump) January 13, 2018

The president was at his golf course in Florida shortly after the false alert -- apparently caused by a state emergency management employee pushing the wrong button -- sent Hawaii residents panicking. It took Hawaii emergency officials 38 minutes for residents to receive an alert notifying them the previous alert was a false alarm.

Mr. Trump was briefed on the incident.

"The president has been briefed on the state of Hawaii's emergency management exercise," a White House official told CBS News. "This was purely a state (controlled) exercise."

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The Federal Communications Commission, according to FCC Chairman Ajit Pai, is launching a "full" investigation into the false missile alert.

Sen. Brian Schatz, D-Hawaii, is calling for an independent review of the incident.