Billions of citizens worldwide rely on disaster apps, which provide quick and concise warnings about fires, floods, and earthquakes. These programs can save lives, warning people out of dangerous areas and helping connect communities during frantic times. You probably have one or two running in the background right now, just in case.

But even apps can cry wolf. Such was the case at 5 pm today in Tokyo, when a number of residents received an alert on their phone that just said, alarmingly, “Earthquake! Earthquake!”

“Users of the Yurekuru disaster warning app were told that a magnitude 9.1 earthquake was about to hit the sprawling metropolis,’” Agence France-Presse reports. Along with the cries of “earthquake,” users were treated to a map of the country, most of which was absolutely swarmed with bright pink quake indicators. About five million people in Japan use the app.

Thanks to a faulty seismometer east of Tokyo, Japan’s Meteorological Agency had sent out an alert, though they immediately withdrew it. It is unclear where along this chain of events the wires got crossed. Yurekuru has since apologized via a message on their support site. “I am sorry to cause you worry,” it reads, in part.

Those worriers affected may need a little while to get their heart rates back down. “When I saw the Yurekuru app screen, I prepared to die,” one user tweeted. Deep breaths and solid ground for everyone.

Every day, we track down a fleeting wonder—something amazing that’s only happening right now. Have a tip for us? Tell us about it! Send your temporary miracles to cara@atlasobscura.com.