If you are one of 0.08% Gmail users that account has been affected by "Bugs" that's about 150,000 Gmail account holders basically woke up to a nightmare this weekend, with all their e-mail, attachments and Google Chat logs went awol, and yes, just like them Democrats in Wisconsin. Now Google is promising Gmail users whose accounts reset this weekend that they will have their lost data restored soon. (thank God I am not one of them).
  In an official blog post, Google claims the "problem" only affected less than 0.02% of Gmail’s user base, but it was a particularly nasty one as it affected more than one copy of the data.
 Google’s Ben Treynor explains how the company can restore the data: “To protect your information from these unusual bugs, we also back it up to tape. Since the tapes are offline, they’re protected from such software bugs. But restoring data from them also takes longer than transferring your requests to another data center, which is why it’s taken us hours to get the email back instead of milliseconds.”

If you are one of the users affected by the bug, Google says your e-mail will probably be back “soon.” so no need to panic. Meanwhile google "gmail back up" and start backing up your gmail. so you can avoid panic attack in the future.