On May 30, 2019, a power outage along several train lines in Japan's Kyushu region halted dozens of trains and inconvenienced thousands of passengers.

The culprit turned out not to be human error or mechanical failure, but a single tiny slug.

Slug was burnt to death after short-circuiting train lines

Japan, well-known for its efficient and punctual transport system, had to cancel 26 train routes on that day, resulting in chaos for roughly 12,000 commuters.

The lines were operated by Kyushu Railway Co. (JR Kyushu), and the blackout lasted an hour, reported The Japan Times on June 24.

Only weeks later was the reason behind the power outage discovered, in the form of a dead slug.

JR Kyushu revealed that the tiny creature had made its way into an electrical power device installed near the railway tracks, called a disconnector switch.

When the disconnector switch was opened, crews from JR Kyushu found the slug, which had reportedly been burnt to a crisp after short-circuiting the device.

It was speculated on Sora News that the slug had managed to squeeze and compress its slimy body into a tiny gap in the casing of the disconnector switch.

Here's a good example of how a slug can squeeze into such a tiny space.

Once inside, it must have touched a cable, resulting in a blackout along entire sections of the railway.

The incident has been described as "rare" by a JR Kyushu official.

The operator also added that it had checked other similar devices in the area, and confirmed that there had been no other slug invasions.

Unlikely creatures are known to cause power outages—squirrels regularly cause power disruptions in the US, and in 2012, a snake that got zapped in a substation in Alabama affected 6,800 people in the area.

Top photo from Pixabay and sodai gomi / Flickr