Screenshots bouncing around social media show alerts reading, in all caps "BALLISTIC MISSILE INBOUND TO HAWAII".
The alert sent people scrambling for shelters and their cars, and online for additional news.
The 8 a.m. HST emergency alert message appeared on cell phones across the state and almost set off a panic.
Brian Schatz says a false alarm about a missile threat was based on "human error" and was "totally inexcusable".
Hawaiians woke up to emergency alerts on their phones today about an imminent ballistic missile attack which they later learned was a false alarm.
Is Apple responsible for smartphone addictions?
This statement of company came after a shareholder wrote to Apple regarding the children protection flaws in their devices. It added: "We think deeply about how our products are used and the impact they have on users and the people around them".
There's no missile headed for Hawaii, Democratic representative Tulsi Gabbard said, after residents in the state received emergency alerts on their mobile phones advising them to "seek immediate shelter" from an inbound ballistic missile.
The message was accidentally sent at 8.07am local time (6.07pm GMT).
HEMA spokesman Richard Repoza said it was a false alarm and the agency is trying to determine what happened.
Hawaii's Emergency Management Agency then quickly announced that the message was a mistake. "Last fall, Hawaii started having drills, but no staff told us this". "I asked a managerial type near the lobby where we should go and he said we could all go to the banquet hall he was in".
"There is no missile threat or danger to the State of Hawaii. Repeat. False alarm", the message said.