Himalayan glacial lake with the skeletons of 600-800 people from c. 800 AD, who all appear to have died from blunt impacts to the head — likely massive hail.
From Wikipedia
Skeleton Lake is a lake in the municipalities of Huntsville and Muskoka Lakes in the District Municipality of Muskoka, Ontario, Canada, about 17 kilometres (11 mi) west of the town centre of Huntsville. Up until 1991, the Ministry of Natural Resources operated a fish hatchery on the lake.