Why did my iPhone stop working after plugging it into the charger?

So I had my iPhone 5 in it's Alpatronix battery case while I was washing my car. It didn't seem like any water got on it until later when I was talking to someone and the speaker sounded static-y. But this was the only thing wrong with the phone. However, about an hour later it sounded fine.

I turned on the battery case and then about an hour later I plugged the phone and the case to the case charger. I'm pretty sure the case was still on, as I forgot to turn it off.

As soon as I plugged it in, the screen flashed for split second and then went dark. No good-bye screen or anything. I took it off the charger and found that no matter what I did, it wouldn't turn on. Please help:(