I found a source saying that the perfective counterpart of падать is both упасть and пасть, so I was wondering what the difference between these two words is.
So far I could only find a post explaining the difference between падать and упасть (the first one is imperfective and the second one is perfective) but I couldn't find anything on the difference between пасть and упасть (though упасть seems to be more commonly used).