a little bigger pictures would be nice. Looks like there is a lot of corrosion. I think I even see a crack that extends from the hole.
I agree. The corrosion looks extensive enough that it makes me think that it may have been the reason that the section failed.
Mcanty, did this happen while you were sailing in a storm or were you moored? Did something catch on a shroud and pull it to cause this to happen?
I would recommend that you have a rigger or a surveyor that you trust take a look at the spar and give you their thoughts before you go through a lot of work and/or expense to repair it.