Mont Blanc glacial lake outburst flood

Background. Saint-Gervais-les-Bains is a commune in southeastern France, situated in the Haute-Savoie department. The event involved a glacial lake outburst flood, a type of outburst flood caused by the failure of a dam containing a glacial lake or the release of water dammed by a glacier. The specific incident occurred on the slopes of Mont Blanc, above the town.

Event Details. The disaster began during the night of 11 July 1892 when an underground water pocket burst from the Tête Rousse Glacier. The resulting flood swept through the immediate valley, passing through the hamlet of Bionnay. While the local school and other buildings in Bionnay survived, the floodwaters bypassed the town of Saint-Gervais and struck the Thermal establishment in Le Fayet.

Impact. The flooding caused significant loss of life, with approximately 200 people killed in its path. The victims were primarily located in the Thermal establishment, which was functioning as a residential facility at the time. The event is recorded as a major disaster for the commune of Saint-Gervais-les-Bains.