A recent power outage at an Amazon AWS data facility in North Virginia led to 7.5% of the EC2 instances and EBS volumes becoming unavailable. Amazon determined that some instances and volumes incurred hardware damage and the data stored on them were no longer recoverable. The loss of data is a good lesson for anyone who hosts their data in the cloud. For example, Amazon Elastic Block Store is an Amazon service that allows you to create block-level storage volumes that can then be attached to Amazon EC2 virtual machine instances as storage.
Source: https://www.bleepingcomputer.com/news/technology/amazon-aws-outage-shows-data-in-the-cloud-is-not-always-safe/