Google confirmed that after a lightning struck the local power grid four times in a row last August 13, 2015, data has been wiped from the discs in one of its Belgium data centers.
After the incident, many users experienced problems for several days and some people lost permanent access to the data on the affected disc. However, through the help of some backup technologies, some data were recovered and became accessible again for the lucky users.
Google said that only 0.000001% of the data disk space was affected and since the Google clients store date in the cloud, identifying what type of data was lost and which clients were affected is impossible. The company added that it is impossible to have a full recovery of the lost data.
While the data centers of Google were designed to endure lightning, there is still a chance for the lightning strikes to get through. Google data centers need more protection against lightning as compared to other buildings.
Google takes full responsibility and considers enhancing the hardware and upgrading its response procedures to minimize data losses in the future.