In July 2010 a pocket containing 50,000 cubic metres of water was detected in a glacial pocket, and some 48,000 cubic metres of water were pumped out. A siren warning system was installed to aid evacuation of those at risk in the valley below, and evacuation plan was put in place. The final section of the Mont Blanc Tramway from St Gervais to Nid d'Aigle was closed for safety reasons for the rest of the operational season, as was the adjacent Nid d'Aigle mountain refuge.