(CNN) The Hawaii Emergency Management Agency employee who triggered the false ballistic missile alert earlier this month has been fired, the state adjutant general said Tuesday.

The unnamed employee said he didn't know it was an exercise, even though five other employees in the room heard "exercise, exercise, exercise, which indicates that it is a drill," an investigating officer told reporters.

Retired Brig. Gen. Bruce Oliveira said, "When it became apparent that the real-world alert was issued," the employee who pushed the button "seemed confused, he froze and another employee had to take over his responsibilities."

The employee "had a history of confusing drill and real-world events," Oliveira said.

The firing was the latest fallout after an internal investigation found "that insufficient management controls, poor computer software design and human factors contributed" to the alert and a delayed correction message on January 13.

Maj. Gen. Joe Logan, Hawaii's state adjutant general, said Vern Miyagi, administrator of the state emergency management agency, resigned Tuesday.

Miyagi accepted full responsibility for the incident and the actions of his employees, Logan said. Another employee is in the process of being suspended without pay and a third employee resigned before any disciplinary action was taken, Logan said.

Logan said he appointed Brig. Gen. Moses Kaoiwi, director of joint staff with the Hawaii National Guard, as interim agency administrator.

Recommendations are released

Oliveira made two dozen recommendations, including eliminating practice drills during a shift change, stronger confirmation prompts for those sending an alert and improved training.

Oliveira's findings echoed an earlier Federal Communications Commission report.

The FCC report said the emergency management worker thought the state was under attack and sent out the warning that sent residents into panic.

"Many things went wrong in Hawaii," FCC Chairman Ajit Pai said in a published statement . "I don't say this for the purpose of casting blame or disparaging Hawaiian officials. We simply need to identify the problems in order to fix them -- not just in Hawaii, but anywhere else where they may exist."

The warning worker said he heard "this is not a drill" but did not hear "exercise, exercise, exercise" in the drill call and sent out an incoming ballistic missile alert throughout the state, according to the FCC.

"According to the written statement, this day shift warning officer therefore believed that the missile threat was real," the FCC said.

The worker would not speak to FCC officials in person and submitted the account of the incident in writing, the report noted.

The event sent the state into panic for 38 minutes until officials sent out a message saying the warning was a mistake.

Gov. David Ige came under criticism over the delay and he later said that he couldn't hop on Twitter because he forgot his password.

Asked at Tuesday's press conference whether he showed a lack of leadership, Ige said: "We are definitely committed to providing a warning to the public of impending natural or manmade disasters."

"We already made the changes required to assure that it never happens again," the governor added.

Chaos on January 13

About 8:06 a.m. on January 13, one employee initiated the ballistic missile alert drill around the time of a shift change at the emergency operation center. The words "exercise, exercise, exercise" were uttered, which is the normal procedure for such drills, an incident timeline said.

The fired employee later incorrectly activated the "real-world" alert code.

Alert messages appeared on the cell phones of agency employees, setting off a series of phone calls to the operations center.

"There is no ballistic missile threat to Hawaii -- this is a drill," one employee at the center later broadcast to counties on a warning system, according to the timeline.

At one point, one employee directed the fired employee to send out the cancel message on the alert system. But the fired employee "just sat there and didn't respond," the timeline said. Another employee seized the fired employee's mouse and sent out a cancellation message.

"At no point did Employee 1 assist in the process."

News media were contacted and the state agency reached out to local, state and federal officials. It also tweeted that there was no missile threat.

About 8:45 a.m. -- 38 minutes after the false alert went out -- a message was posted through the emergency alert system on local television, radio and audio broadcasts, and a television crawler banner. The message said: "False Alert. There is no missile threat to Hawaii."

FCC' Hawaii didn't have 'reasonable safeguards'

There were two "troubling things" in the FCC preliminary findings, Pai said.

The state "didn't have reasonable safeguards in place to prevent human error from resulting in the tranmission of a false alert," the statement said. The second main problem, Pai said, was there was no plan of action if a false alert went out.