The Large Hadron Collider particle accelerator at CERN has shut down after a short circuit – caused by a weasel.
However, the creature was not fortunate enough to survive the encounter with a high-voltage transformer at the site near Geneva in Switzerland.
The LHC was running when a “severe electrical perturbation” occurred in the early hours of Friday morning.
A spokesman for Cern said that the weasel did not get into the tunnels, just the electrical facilities.
Addressing press media, Arnaud Marsollier said that it would take some days before the damage caused by the weasel’s visit is fixed soundly.
He added that while it was, fortunately, not every day that an animal affected the equipment, it was not that surprising as the research facility is in the countryside.
In 2009 the LHC was taken out by what was suspected to be a bird, though no remains were found.
Such “small issues” with the equipment were all part of the running of the LHC, Mr Marsollier said, and experts were used to carrying out repairs.
CERN’s own report on the incident says that the weasel got into a 66kV transformer. The transformer connections were damaged.
“Not the best week for LHC!” it says.