Residents of Hawaii received this warning on their smartphone screens Saturday morning from the Hawaii Emergency Management Agency. Photograph Caleb Jones / AP

A little after 8 A.M. today, Hawaii Standard Time, an alert was sent to cell phones in Hawaii: “BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL.” The message was also broadcast on local television and radio.

Nearly forty minutes passed before a second message went out: “There is no missile threat or danger to the State of Hawaii. Repeat. False Alarm.” Later, the governor of Hawaii, David Ige, told CNN, “It was a mistake made during a standard procedure at the changeover of a shift, and an employee pushed the wrong button.”

Brook Conner, a forty-nine-year-old cyber-security expert, moved to Hawaii from New York in September with his wife and their three-year-old daughter. “Having lived through 9/11, danger wasn’t necessarily a change for us. But, at the time, our thinking was, Hawaii is a very small target. It’s well defended. And very far away from anything else. So if the missiles start flying, and they’re crappy North Korean missiles, maybe they’ll just miss.”

Two hours after the alert was rescinded, with his heart rate still elevated, Conner described the roughly half hour that he and his family spent thinking that nuclear Armageddon was upon them. His account has been edited and condensed.

“Our apartment looks out over the international airport and Pearl Harbor. Whenever there’s fighter-jet activity, it goes right by our lanai. There’s been a lot of exercises recently. The local news has been reporting why so many fighter jets are running around, and the stories described the name of the exercises: Sunset Aloha. Apparently, they’re military drills. What it meant, for us, is F-22s and F-35s have been screaming through the skies over the past two weeks.

“We were sitting out on the lanai when the announcement came over the building speaker that there was an inbound ballistic missile to Hawaii. And that it wasn’t a drill. They repeated that. I got a text from a friend who’s an airline pilot who runs a Honolulu route and happened to be in town saying, ‘Did you guys see this?’ My wife called a friend of hers on the Big Island to see whether it was something that was just Honolulu, just Oahu, or the entire state. She was able to get through, and her friend said ‘Yes, it’s for the entire state.’

“At that point, we secured all the windows and all the doors. We started filling the tubs and every container we could with water. And texting family and friends. There’s been an increasing amount of information in Hawaii about what to do in case of a ballistic missile, over the last few months, clearly tied to tensions with North Korea. Everybody in Hawaii is very aware that after Guam we’re the next-closest target. We’re the only part of the U.S. that’s been a target of a military attack by a foreign power in the past century. And, of course, coming from New York, being the target of a non-military attack, that resonated with us in the worst possible way. Hawaii has also started doing monthly air-raid drills.

“It took me maybe a minute to process that this was actually happening. It was an ‘Oh my god, but I need to execute, I need to get things done’ kind of feeling. ‘Is this real? Can this really happen? They’re gonna shoot it down, right? What happens if our building collapses and we can’t get to our little girl?’

“After about five minutes, we were visibly upset. My wife was crying, and George, our daughter, wanted to know why. We asked her to come over for a family hug. We explained that we’d heard very bad news that something very, very bad was happening and it had us really, really upset. I don’t think she really understands nuclear Armageddon or ballistic missiles, but she certainly understands that Mommy and Daddy are really upset.

“We continued to fill every container we could find with water for maybe another fifteen or twenty minutes. We tried calling people. My wife tried her father in Chicago three times, got a busy signal. I texted my mother and my twenty-one-year-old daughter. We texted the rest of my wife’s family to say there’s a ballistic missile coming towards Hawaii and it’s not a drill.

“I’m not a religious person. There are no prayers to God in our household.

“At eight twenty-nine, we got a text back from my wife’s brother saying it was a hoax. Half an hour had passed, roughly. Then I checked and started seeing reports on Twitter from Tulsi Gabbard and other reps, from the governor, saying this was a false alarm. Then we got an alert over the building loudspeaker also saying it was a false alarm. Then we got the cell-phone alert. At that point, I was able to get through to my mother on the phone. She reported that what she saw on the news in the mainland was nothing until finally they said, ‘Oh, there’s a false alarm of a missile coming into Hawaii.’ Meanwhile, everyone over here is really upset and thinks they’re all going to die. Our friend the pilot was in a hotel saying the lobby was full of crying children.

“We began to relax a little and start to deal with the aftereffects of a severe adrenaline rush. I’m still shaking, though. My wife is still having waves of goose bumps and chills periodically. I’ve been part of cyber-security emergency responses, so part of my thinking was, What can we possibly learn from this? We need to make sure that both the alert procedure, which clearly had some problems, and response procedures—which hopefully all worked well, but I don’t know—that those are all tied up. I’d hope that with the initial lack of reporting by the mainland media, that people would take this as a scare to say, ‘Let’s calm this all down. Nuclear war is not gonna be good for anybody.’

“We’re going to brunch now in a neighborhood nearby called Kaka‘ako. We’re walking over, rather than driving, in a few minutes. Mai Tai cocktails are on order.”