"The employee who transmitted the alert said in a written statement to Hawaii that he or she believed it was an actual alert"

Reuters:

The U.S. Federal Communications Commission on Tuesday faulted the Hawaii Emergency Management Agency’s procedures over a false emergency alert on January 13 of a pending missile attack that prompted widespread panic.

WaPo:

The Hawaii employee who sent out a false alarm earlier this month warning of an incoming missile attack had a troubled work history and said he misunderstood a drill and believed a ballistic missile was actually heading for the state, according to state and federal investigators.

The employee's work history was detailed by a state investigation made public Tuesday that found he had "been a source of concern ... for over 10 years" to his coworkers. On at least two other occasions, that probe found, this employee also "confused real life events and drills."