The Federal Communications Commission and the Hawaii House of Representatives launched investigations into the incident, leading to the resignation of the state's emergency management administrator.

[2][3][4] North Korea had conducted several intercontinental ballistic missile tests over the past year, most recently in November 2017,[5] enhancing its strike capabilities.

[13] Testing of the civil defense warning sirens and attack drills were also conducted in the state on the first business day of the month beginning in December 2017.

[21] Vern Miyagi, the administrator of the Hawaii Emergency Management Agency, explained that state leaders "couldn't ignore these constant threats and missile tests from North Korea" and felt the need to prepare residents for the possibility of an attack.

[38] Vern Miyagi, then-administrator of HI-EMA, said the alert had been inadvertently triggered by the employee as he was working at the Diamond Head Crater headquarters[39][40] during a shift change.

[39] During the shift change, a supervisor ran an unscheduled drill[40] in which he contacted emergency management workers in the guise of an officer from U.S. Pacific Command, according to state officials.

[48] The employee later claimed to the Associated Press that he had not heard the "exercise" part of the phone call because a co-worker had placed it on speakerphone partway into the message, and as a result, he had been "100 percent sure" the attack was real.

[42] By 8:10 a.m. HST, three minutes after the first alert, Hawaii National Guard Adjutant General Arthur "Joe" Logan had contacted U.S. Pacific Command and confirmed there had been no missile launch.

Hawaii Emergency Management Agency accounts on Facebook and Twitter posted messages at that time urging people to disregard the erroneous alert.

[26][51] During the 38 minutes between the first and second alerts, Hawaii's siren warning system—which had been tested as part of a missile preparedness exercise the previous month for the first time since the Cold War[57]—was not formally activated.

[56] Some commercial flights were reportedly delayed for a short time, although the Hawaii Department of Transportation said there were no widespread impacts at the state's airports and harbors.

[62] Hawaii News Now reported that alarms sounded at Aloha Gymfest, an international gymnastics meet in Kailua, sending hundreds of people running for cover.

[12] Officials at the Sony Open PGA Tour golf tournament on Oahu ordered an evacuation of the media center, while staff members sought cover in the kitchen and players' locker room.

[58][63][73] Others remained where they were, as with Mark Gardner, who, believing that escape was impossible, recorded a final message to his family in anticipation of the missile striking its target.

Many Twitter posts and screenshots of text messages shared on social media in the immediate wake of the first alert conveyed confusion, alarm, and fear among those who received the warning.

Congresswoman Tulsi Gabbard tweeted at 8:19 a.m. HST, about 12 minutes after the initial alert was sent, stating in all capitals that the message was a "false alarm" and that she had confirmed with officials that there was no incoming ballistic missile toward Hawaii.

Homeland Security Secretary Kirstjen Nielsen said the incident was "unfortunate" and officials were working to prevent a similar false alert from being issued in the future.

[60] Speaking on Fox News the next day, she said people "can trust government systems" and should pay attention to any alerts they receive from authorities in the future, in spite of the January 13 incident in Hawaii.

[23][24][92] He blamed Hawaii's government for not having "reasonable safeguards or process controls in place to prevent the transmission of a false alert",[93] later stating that other agencies should "learn from these mistakes".

[38] Congresswoman Tulsi Gabbard stated in an interview after the second emergency alert was sent that the incident was "a taste of the stark reality of what we face here of a potential nuclear strike on Hawaii", referring to the possibility of a North Korean attack.

I, too, am extremely upset about this and am doing everything I can do to immediately improve our emergency management systems, procedures and staffing.Hawaii Senate Majority Leader J. Kalani English said he was "outraged" by the error, which caused unnecessary "panic and pandemonium" throughout the state.

[45] State officials placed former Hawaii Army National Guard commander Bruce E. Oliveira in charge of internally investigating the events that resulted in the false alert being sent out.

In his report, published January 30, Oliveira faulted "insufficient management controls, poor computer software design, and human factors" for the incident.

[41] Hawaii Emergency Management Agency head Vern Miyagi initially declined to say whether the employee, who he said felt "terrible" about the false alert, would face discipline.

[54] An agency spokesman said January 14 the employee had been "temporarily reassigned" to a position that did not allow him access to the emergency warning system, pending the result of the internal investigation.

[99] The FCC report, released January 30, faulted the state for failing to quickly notify the public and not having safeguards in place sufficient to prevent the error.

… The public needs to be able to trust that when the government issues an alert it is indeed a credible alert.Miyagi resigned as HI-EMA administrator the same day the state and federal reports were released.

[101] The agency also moved quickly to implement a cancellation command that officials said can be triggered within seconds of an erroneous alert being sent out, which it reportedly lacked before the January 13 incident.

[103] In July 2018, the FCC issued a report and order which makes changes to EAS regulations to "improve the integrity, efficacy, and reliability" of the system and "minimize the potential for false alerts".

[107] An official with the Division of Homeland Security & Emergency Management in the U.S. state of Alaska, also within the theoretical range of North Korean nuclear missiles, said his department encourages Alaskans to shelter in place rather than trying to get elsewhere if there is an attack, as many people in Hawaii did after the false alert was issued.