Note: This is a very similar question to this:
Did eight Jesuit priests survive the nuking of Hiroshima in a scientifically inexplicable manner?
However, since in spite of their parallelism these are actually two different events, I've finally decided to ask two questions instead of one.
It is being frequently claimed by Catholic sources (e.g. Catholic Herald) and even Wikipedia that Franciscan friars survived the nuking of Nagasaki because of the friary being protected from the blast by a mountain. It is also claimed that st. Maximilian Kolbe had built the friary in this place contrary to what he had been advised. It is claimed that Maximillian Kolbe must have had some prior knowledge about the exact location of the nuclear blast.
Did the Franciscans really survive the blast?
Was the peculiar location of the friary the primary cause of their survival according to contemporary science?
Was Kolbe's decision to erect the friary in this peculiar location odd? I mean, can it be maintained that in all probability anyone in Kolbe's position would likely erect the friary elsewhere?