Default Mini won't turn on.

My Droid Mini won't turn on. It's running KitKat, No root. Battery was around 50%, couple minutes later, I try to use it and it won't respond, screen won't come on. I tied holding power and vol up 20 seconds, and tried the same for power and vol down. Nothing. I have it plugged in and it's not doing anything.
I'm nervous about sending it to Verizon to replace it since I side loaded KitKat. But everything was running fine. Any ideas?

PS I searched and couldn't find a thread to help, if there is one, sorry, please post a link.