An investigation is underway to determine the cause of a data centre fire in the French city of Strasbourg that resulted in the loss of data and service outages across Europe.

The fire tore through one building and partially damaged another on a site operated by French cloud firm OVH.​

The cause of the fire is yet to be established, but an investigation has been launched.

The incident was first reported just before half three on 10 March (UTC) and although firefighters responded almost immediately they were unable to stop a blaze inside OVH’s SBG2 building. Four rooms inside SBG1 were also destroyed in the fire.

Two other data centres owned by OVH were not affected by the fire, but the company has had to switch off every one of its servers.

“If your production is in Strasbourg, we recommend to activate your Disaster Recovery Plan,” the firm warned. “All our teams are fully mobilised along with the firefighters. We will keep you updated as more information becomes available.”

OVH has reserved servers at other cites in Roubaix and Gravelines that are ready to support the majority of its affected customers, and an additional 10,000 new servers are already in production. The company added that an official customer announcement and FAQ will be posted on its website soon.

OVH also said it is currently working on a plan to relaunch the two unaffected data centres in Strasbourg, and potentially the partially damaged one, once the site is secured and reconnected to power.

“We ask that our customers exercise caution around the emails they receive: in times of crisis, it is common for malicious activity (phishing, spam, etc.) to increase,” OVH warned. “It is more important than ever to stay alert.”

OVH has become a popular cloud provider in recent times, with 27 data centres in operation, mainly across Europe. The firm is also set for IPO later in the year.

A number of its customers have taken to Twitter to report downtimes due to the fire. These include digital asset management library Piwigo, gaming cite Rust, and reportedly the French Government.

A tweet from Russia’s media watchdog, Roskomnadzor, suggested the outage also took down Google services, including YouTube, in Russia. However, a Google investigation later found that this was due to an upstream network issue and was entirely unrelated to the OVH fire.​