iPad won't turn on after a complete battery drain

I forgot to plug in my iPad after the critical battery warning and it went some minutes following the warning. I was not worried because same thing had happened a few times before and iPad was perfectly okay after charging it. However, this time I remember seeing a flash of blue screen immediately after it went black. Then, I plugged it in an waited for a while and tried starting it. Ever since, it fails to start hanging on the apple logo with white background screen. I tried to connect to my Mac but nothing showed up in iTunes. I am worried now. What could have happened? my iPad is out of warranty. It is an iPad mini retina.

Thanks in advance.