Photos released from the Nepal and Tibet border show terrifying moments; people fleeing from a wall of water, mud, stones, and ice.

On Wednesday morning, 5 Shahrivar, a massive section of a natural glacier in the Himalayas collapsed, unleashing a deadly flood. The flow began around Langtang National Park and near the Gyrong pass, and moved along valleys and rivers toward Rasowa and Bidor.

The flood killed at least 165 people and left more than one thousand missing. Scientists are still investigating the exact cause of the disaster, but a more serious question has emerged: was this only an exceptional accident, or a warning about the instability of natural glaciers in the age of climate change?