A small mammal, identified as a weasel, caused a short circuit on a 66-kV transformer at the Large Hadron Collider (LHC) near Geneva on April 29, 2016, around 5:30 a.m. The incident led to the LHC being put on standby, with the shutdown lasting several days, according to CERN. Some reports estimate the shutdown could have lasted up to 8 days. The animal entered the transformer and damaged connections, causing an electric arc that slightly damaged some connections, according to CERN spokesperson Arnaud Marsollier. The LHC, located approximately 100 meters underground, was not damaged beyond the surface electrical installations, which are vulnerable to animals. The incident occurred as the LHC was being brought back online after several months of winter shutdown, and before the technical shutdown of the previous year, when researchers were examining intriguing anomalies that required more data. This was not the first time an animal had caused an issue at the LHC; in 2009, the collider was interrupted by what was believed to be a bird, with no remains found. A version widely reported by specialized press suggests that the animal had dropped a piece of a stick on an electrical post. The story first leaked through slides detailing recent tests of the LHC circulating online and on Reddit, with the word "weasel" written in all caps. CERN confirmed the incident on April 30, 2016, through its spokesperson to AFP. The animal did not survive, and there would not be much left of it, indicated CERN. The spokesperson noted that the animal had never reached the tunnels, only the electrical installations on the site.