Sometimes behavior of geckos towards each other may change. I had two females, that were totally OK, no fighting, sleeping together in one place and so on. But when they started laying eggs, both were doing so in exactly same spot, so one female started to dig out eggs of the other and lay there...
I'm sorry for your loss :( Hope it will get better over time. This seems to be really bad summer for you, but don't get too depressive, it just happened, now you can't change it. I don't think that you should forget what you've been through, but just not to get stuck in the past and what could...