Date: January 24, 2014
Duration: About an hour
Failure: When Gmail goes down, people notice. When Gmail, Google Calendar, Google Docs, and Google+ go offline, people really notice. (Okay, maybe not so much Google+, but definitely the others.)
On a Friday in January, several Google services simultaneously took a snooze. Google says a software bug on its end caused the glitch: According to engineers, a system that controls the services sent faulty configurations to a variety of servers, which resulted in widespread errors.
Google had everything back up and running for most folks in about 25 minutes. For some users, it took 30 minutes to an hour for services to get back online.