A little after 1 yesterday I noticed my Google Calendar feed was throwing error messages like crazy, then Gmail started too. Then my Chrome browser shut off. At first I thought it was just a very weird coincidence, but Google later reported they were all part of the same error.
Essentially Google Sync (which syncs your account setting across all things Google) hit a server error that caused an error in the browser itself causing it to crash the browser all together.
This is quite a rare and unique event. I’ve never heard of any cloud service problem actually crashing a browser itself, but I guess yesterday proved it’s possible.