HONOLULU — A false alarm that warned of a ballistic missile headed for Hawaii sent the islands into a panic Saturday, with people abandoning cars in a highway and preparing to flee their homes until officials said the cellphone alert was a mistake.It wasn't clear exactly what happened — House Speaker Scott Saiki said someone pushed the wrong button, and the White House said the episode was "purely a state exercise."But for nearly 40 minutes, it seemed like the world was about to end in Hawaii, an island paradise already jittery over the threat of nuclear-tipped missiles from North Korea.The emergency alert, which was sent to cellphones statewide just before 8:10 a.m., said: "BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL."On the H-3, a major highway north of Honolulu, vehicles sat empty after drivers left them to run to a nearby tunnel after the alert showed up, the Honolulu Star-Advertiser reported. Workers at a golf club huddled in a kitchen fearing the worst.Professional golfer Colt Knost, staying at Waikiki Beach during a PGA Tour event, said "everyone was panicking" in the lobby of his hotel."Everyone was running around like, 'What do we do?'" he said.Richard Ing, a Honolulu attorney, was doing a construction project at home when his wife told him about the alert. His wife and children prepared to evacuate while he tried to figure out what was happening.Cherese Carlson, in Honolulu for a class and away from her children, said she called to make sure they were inside after getting the alert."I thought, 'Oh my god, this is it.