I'm with Davie, it's 2, 3, 6 in that order.
On 2-I lived in the western slope, the rough Rockies. Could definitely see that happen especially with Elk or Caribou and then there would be nothing in the picture but a bit of debris! I can't believe I never pondered that possibility!
On 3-Dog lover with 3 of my own (Crestie mom). What an adorable face. Wish mine would get board like that!!
On 6-There's a person who never studied physics! LOL!