Summary of the AWS Service Event in the US East Region (July 2 2012)
aws.amazon.com/message/67457
What Jamie wrote
Power problems.
Wed like to share more about the service disruption which occurred last Friday night, June 29th, in one of our Availability Zones in the US East-1 Region. The event was triggered during a large scale electrical storm which swept through the Northern Virginia area. We regret the problems experienced by customers affected by the disruption and, in addition to giving more detail, also wanted to provide information on actions well be taking to mitigate these issues in the future.