Rich Miller at Data Center Knowledge reports that a lightning storm knocked out power to part of Amazon's EC2 cloud computing services.
Some customers were offline for more than four hours before the damage could be repaired.
The problems began at about 6:30 pm Pacific time, and most affected customers were back online by 11 p.m., according to Amazon’s status dashboard. The company said the outage was limited to customers in one of Amazon’s four availability zones in the U.S.
(I'm always on the look out for "ironic design" as showing the hand of a creator :)
This incident might convince some potential cloud computing customers to keep things in-house. However, the same type of thing could happen to any data center whether it is your own or in the cloud.