Is it my fault?

[zina10]

I'm sorry for your loss, but I agree with the others. Even without any water at all for a week and a half. That wouldn't kill an otherwise healthy Ball Python. They can go far longer then that without water.

Either something else went wrong, like the heat spiked, or the snake had underlying issues that ended up killing it.

If it appeared completely healthy prior to your leaving and would eat regularly, I would double check the heating.

Being to cold will make a BP sick in the long run, but not kill it quickly. To hot on the other hand, certainly can..

You sound like a caring pet owner. Just double check all the husbandry, then deeply and thoroughly sanitize EVERYTHING with either a product like F10 or a bleach solution. If bleach solution, rinse and dry everything. (F10 you just wipe off)

Once everything is sanitized, aired out and double checked, get another Ball Python. It will have a good home with you.