A GLOF occurred on this lake on the 3rd of september 1998 following an earthquake which caused the fall of séracs in the lake.
These séracs generated a wave which is at the origin of the rupture of the lake. The water volume that was poured down the valley is huge, almost 18 million of cubic meters, The height of the flood wave over the village located 1 km downstream is estimated at 10 meters. Important rock debris resulting from the GLOF are visible13 kilometers downstream.
The peak flow reached 14000 cumecs or 8 times the Rhone's mean flow.