GMail not working

Today, I woke up at 5.30 am, opened my GMail account and started attaching some files to a mail, then I saw that after some time each attachment uploading was getting failed, I retried many times, then I refreshed my Gmail page and observed that GMail was down. It was my first ever personal experience that it was not working for me. I am not sure about what happened at that time but I get following error messages while working on it.

After refreshing my page, I got this-