But beyond a bad look, human error is also not a terribly informative explanation for the spike in anxiety the message created. That’s largely because emergency notifications have become so efficient. Too efficient, maybe.

In 2013, FEMA replaced the Commercial Mobile Alert System with Wireless Emergency Alerts (WEAs). These are the messages you receive on your smartphones today. They include AMBER alert notices for child abductions, government emergencies including weather and, God help us, ballistic-missile attacks, and direct messages from the president. If you look carefully at your smartphone’s notification settings, you’ll see that you can disable the first two kinds of alerts, but not the third—which has never been used since the conception of all these systems in the mid-20th century.

Consider Gaither’s account of how his family learned about the fictional missile attack. “We’re an iPhone family and all our devices shrieked Amber-style alerts at the same time.”

Most people have had just this experience. IPAWS messages include an allocation for WEAs, which are sent directly to participating wireless carriers. Those messages are pushed to mobile devices active on cell towers in the area where the alert is defined—that’s why you can receive an emergency alert while traveling. Like the old EBS, an ear-piercing sound precedes a WEA, meant to grab the attention of its recipient.

People have their smartphones with them all the time. Even in bed, or nearby. That makes WEAs an effective way to reach people immediately and directly in the event of an emergency. But it also means that there is no slack in the system. The old EBS notices, or any broadcast message sent via EAS, only reached citizens who were watching television or listening to radio at the time it was sent. The system would repeat the messages occasionally, but there didn’t used to be a way to reach so many people all at once. That can be good if the information is sound, or terrible if it is not, as was the case in Hawaii today.

But perhaps the information in a WEA can never be sound, because it cannot be self-contained. A WEA must be 90 characters or less; there’s no room for elaboration or further instruction. The EAS message the Hawaii Emergency Management Agency sent to television and radio broadcasts included instructions for taking shelter, at least—the wireless notice did little more than suggest unvarnished panic. That’s all it can do.

Back in the days of broadcast, emergency-notification messages often instructed affected citizens to tune in to local media for further information and instruction. An emergency notice is mostly a jolt to take action—but what action? And how? And when? And why? In the 1980s or even the 1990s, that would have involved tuning in to radio or television. Even on the morning of 9/11, the internet was useless—servers overtaxed, just as the Hawaii Emergency Management Agency’s were today.