With the utmost respect to the Whistler Ski Patroler that passed away yesterday, this video demonstrates the sensitivity of the snowpack in BC.
Short and to the point, the slide starts at about 0:30. As the credits note, the skier noticed no earlier activity and is well out of the alpine. I wont try to armchair quarterback the angle of the slope, but it doesn’t look particularly steep where the fracture began, and it seemed to propagate with a lot of energy. Be safe out there!