Has this happened to anyone else? What did you do?

So I discovered my checking and savings accounts were drained over the weekend. I stopped my account... which only has about $30 left between the two now... and that's about all I can do for the time being until my bank opens tomorrow. 😬

I guess my question is what do I do in the future? Keep my money stuffed in the mattress? How do I stop it from happening again?