A source of pleasure but also of mortal danger, snow is an unstable, ever-changing substance. It should never be taken for granted.
In Méribel, protecting thousands of skiers from this Damocles sword that can wreak such sudden havoc is a major challenge for ski patrollers.
Here is a look behind the scenes as they mark and perform work with explosives designed to remove all risk. This is known as avalanche blasting.