Google Compute Engine Incident #16007
status.cloud.google.com/incident/compute/16007?post-mortem
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
On Monday, 11 April, 2016, Google Compute Engine instances in all regions lost external connectivity for a total of 18 minutes, from 19:09 to 19:27 Pacific Time.