[TOMT] [MOVIE] [2000s-2010s] Movie about three friends, 2 of them died

When i was a child I saw movie on TV, maybe it was a short movie, there were 3 friends, there were scenes how they had fun, for example, they were hiking with a very big backpacks. Then they were at gas station, playing with gasoline like with water guns, and one of them decided to smoke. 2 of them died (Its not the Zoolander movie), and the one remaining friend was having fun like they had in previous scenes, but he is alone now, and I remember that he was hiking with his big backpack, and he was taking the big backpacks of his dead friends. (Sorry for mistakes)