Part of Japan’s hugely efficient high-speed rail network was brought to a standstill last month after a small slug crawled into electrical equipment.
Some 12,000 passengers were delayed, with 26 trains cancelled, after the creature short-circuited the power in Kyushu, southern Japan.
The power failed on two lines, run by JR Kyushu, because of the slug making its way into an electrical power device.
Officials said they found the slug’s burnt body inside the electrics.
A spokesman said: “We tracked down the device responsible for the power failure. We initially thought what's in there was a bug but it turned out to be a dead slug.”
The official described the incident as "rare,” adding: "We often have trouble with deer colliding with trains but not a problem with slugs.”
Japan has a notoriously reliable railway, with an average delay of just 0.7 minutes.
When trains are delayed by five minutes, commuters are given a certificate proving their lateness to submit to employers.
