Many in Japan were in a brief state of panic earlier this week when the Japan Meteorological Agency issued a fake earthquake warning. Broadcast at around 5pm local time on August 1, rail networks and smartphone users connected to the early warning network were informed that a magnitude 9.1 tremor had just struck the central Kanto region of the mainland island of Honshu.

This quake would have been as powerful as the devastating 2011 Tohoku event, whose once-in-a-century tsunami killed over 20,000 people. This not-quite-there tremor was said to have occurred beneath the Japanese archipelago itself, though, so although a tsunami wouldn’t have been likely, it would have still caused considerable infrastructural damage.

Fortunately, this appeared to have been a technical glitch. According to the Japan Times, a JMA official said that “the quake that had been predicted has not taken place,” and that it was an “error on our part. We sincerely apologize.”

Trains in Japan are known for being not just incredibly efficient, but always on time with very few exceptions. To the horror of some, then, it has been reported that “trains were as much as 10 minutes late” following the erroneous broadcast.

Rumors on Twitter began to spread following the realization that the quake was never going to arrive. Some blamed the virtual tremor on a particularly energetic lightning bolt, whereas others concluded that Godzilla had woken up from a long slumber. Others concluded that the omnipotence of Pokémon Go was the culprit, but it’s likely that we’ll never know for sure.

The JMA also recently warned the residents of Kagoshima, situated on the western island of Kyushu, that Sakurajima was erupting quite violently. That warning, though, turned out to be real.