Four lightning strikes hit the local power grid supplying its European data center last week. Resulting power fluctuations near its Belgian data center designated as the europe-west1-b zone resulted in sporadic disk errors. Those errors in turn led to permanent data loss. Google says that the data loss affected less than 0.000001% of Google Compute Engine Persistent Disk space in the zone. Google is taking full responsibility, but reminded customers that GCE instances and Persistent Disks are all lumped together in one data center.”]
Source: https://nakedsecurity.sophos.com/2015/08/21/google-customers-lose-data-after-lightning-strikes/