The largest and most powerful particle accelerator in the world, the Large Hadron Collider (LHC) in Switzerland, has had its whole system briefly shut down on April 28 because of a small animal. The furry creature did not survive, while the machine itself needs to wait for days to weeks to get back online and in top shape once again.

Engineers from the European physics laboratory CERN believed it was an adventurous weasel that had an unlucky brush with a 66,000-volt transformer, causing a short circuit that shut down the LHC.

Introduced in September 2008, the LHC is the world’s most powerful particle collider tasked to explore the mysterious “dark universe.” It is made up of a 17-mile ring of super-conducting magnets, and inside are two protons or high-energy particle beams traveling nearly at the speed of light before being induced to collide head-on.

LHC discovered the Higgs boson particle, an elementary particle in particle physics, back in 2012, while several experiments last year suggested the existence of a new particle, something not previously observed by science.

CERN spokesperson Arnaud Marsollier told the AFP that the collider suffered “severe electrical perturbation” on April 29, resulting from a short circuit caused by fouine, a European term for a beech marten or a member of the weasel family. Some connections were slightly damaged and the team is now at work – for “no longer than a few days” – to repair the LHC, he added.

The accident had a crucial timing, too, as CERN scientists had been preparing to resume lab experiments sometime this week following a months-long technical stoppage. The LHC was gearing to collect new data on the Higgs boson.

“We will now need to check over the entire machine again,” said Marsollier, something that could delay the re-launch of the high-level hunt for particles. According to him, it is still unclear when the experiments will resume.

While repairs will likely take a few days, getting the machine completely ready to smash might take one to two weeks more, with Marsollier guessing it would be back on track by around mid-May.

This isn’t the first time that an invading animal wreaked havoc on the LHC. Back in 2009, a puckish bird briefly knocked out a section of the collider when it dropped a baguette on the LHC's external electrical power source, triggering a chain reaction that resulted in the cooling system’s shutdown.

Scientists, however, were able to restore the system in a matter of hours. One of the speculations at that time was the baguette had come from the future as a form of sabotage, although CERN scientists thought it unlikely as baguettes likely won’t figure “in future cultures.”

The 17-mile tunnel housing of the LHC plays a key factor as well. It straddles the French-Swiss border and is situated in the countryside, where wild animals such as weasels are a common feature. 

In 2013, a hyperactive pine marten stopped a soccer match as it scampered around the play field in Switzerland, evading many players before being successfully caught.

Marsollier deemed these events an inevitable part of the life cycle of “such a large installation.”