World missing after phone dies

I play on Minecraft PE on my Android phone. I'll play in one world for a while unaware of the battery life of my phone. When my phone dies while I'm playing the world I was working on it disappears from my world list. And since this is an application saved world, instead of external, I can't find any files or evidence of what exactly happened to my world. It's not that it gave me a message that the file was corrupt, it just suddenly disappeared when my phone died. This isn't the first time this has happened to me.