Dive Brief:

• Google reported that four successive lightning strikes on a local utilities grid near one of its cloud infrastructure facilities in Belgium last week wiped out some customers' data permanently.

• Google said the series of strikes occurred on Aug. 13.

• The lightning briefly knocked out power to systems that run virtual machines for customers in the cloud.

Dive Insight:

Google called the incident "exceptional."

"Although automatic auxiliary systems restored power quickly, and the storage systems are designed with battery backup, some recently written data was located on storage systems which were more susceptible to power failure from extended or repeated battery drain," Google said. "In almost all cases the data was successfully committed to stable storage, although manual intervention was required in order to restore the systems to their normal serving state."

However, in a very few cases data was permanently lost, the company said.