The cause of the false alarm? A state emergency management employee apparently pushed the wrong button.

"I know firsthand that what happened today is totally unacceptable, and many in our community were deeply affect by this," Gov. David Ige said, at a news conference at the Hawaii Emergency Management agency on Saturday afternoon.

"I'm sorry for that pain and confusion that anyone might have experienced. I, too, am very angry and disappointed that this happened."

While city and military officials took to social media within 15 minutes to quell fears and say the message was sent by mistake, it took state emergency management — which sent out the message in the first place — 38 minutes to send out a "false alarm" alert to cell phones using the same mechanism that distributed the emergency warning in the first place.

Flights at Honolulu's airport, meanwhile, were suspended for about 18 minutes. 

"It's totally unacceptable," said U.S. Sen. Brian Schatz, D-Hawaii. "There was anxiety across the state and it was terrifying. There was a lot of unnecessary pain and anxiety. It's important to have accountability at the state level and the emergency management level in terms of what exactly what went wrong."

Seconds after the alert was issued, 911 dispatchers were overwhelmed with calls.

Honolulu Police Chief Susan Ballard said dispatchers answered about 3,000 calls before the alert was canceled, while about 2,500 calls were dropped.