Gmail Down 502 Server Error - Google Product Gmail is Down

Gmail Down - 502 Server Error

May 13, 2013, for last few minutes I am unable to access Gmail. I tried many times but every time getting following error:
502. 

That’s an error.

The server encountered a temporary error and could not complete your request.

Please try again in 30 seconds.
That’s all we know.

Gmail on my mobile is also not working. Giving same error 502 Server Error