i'm so sorry for you loss. we all know how hard it is to handle. but if i may add, please don't beat yourself up too much.. we all try to be super careful, but sometimes, we slip up, we are only human afterall.. you did your best to keep him safe. unfortunately, sometimes horrible things just happen... once before when i just had one, chinchin opened his cage door at night when i was sleeping and i had 2 bigs dogs at the time, i found fur all over the house, i thought for sure he was dead.. i was flipping.. when i put the dogs out, the little devil come out from hiding and was fine.. but point being, if he died, that would of been my fault too for not knowing the cage door lock didn't work, but again, we are all human and sometimes things just happen..
the pain will go away with time, but the memories will last your lifetime.
j