brenmcg, Jesus’ prophecy of the destruction of the Temple is not just another random prophecy.   Whether or not it ever happened historically is an interesting question but the more important aspect of the matter is the way Mark uses the prediction in the context of his gospel.  Mark is literature not reportage. Mark is obsessed with the Temple.  (Note that in the 50s Paul, who must have traveled to the Temple many times,  is almost completely silent about it.) 

We must seriously consider the association between Jesus’ death and the destruction of the Temple:

We heard him say, ‘I will destroy this temple that is made with hands, and in three days I will build another, not made with hands.’ 

I know you won’t agree but Mark is looking back on Jesus’ death and looking at the destruction of the Temple and interpreting these events to show their significance from his apocalyptic theological perspective.  For the people in the stories he told, the destruction of the Temple was a future event.  For his audience the destruction of the Temple was a lived reality.  For his audience Mark was associating two events both stuffed full of significance.