In the future, don't go close to mountains during monsoon season - late May to August end; that period is specifically for Southeast Asia. For the rest of the world, you can find it out.
I read this wasn't due to rain but a glacial collapse. It sounds to me like the additional advice would be that due to a warming climate, avoid being under a glacier at all costs?
This was a glacier collapse. https://www.zhihu.com/question/2075969425702741132/answer/20...