PARIS (Reuters) – A fire tore through a data complex housing servers run by cloud computing company OVHcloud in Strasbourg, eastern France, on Wednesday, destroying some units and forcing the temporary shutdown of others, the company’s chief executive said.

OVHcloud, which on Monday had launched the process for a potential IPO, urged clients to activate their disaster recovery plans.

“Fire destroyed SBG2. A part of SBG1 is destroyed. Firefighters are protecting SBG3. No impact SBG4,” Chief Executive Octave Klaba said on Twitter in reference to different units housing servers.

“We don’t have access to the site. That is why SBG1, SBG3, SBG4 won’t be restarted today,” he added.

The data centre in Strasbourg is one of OVHcloud’s 17 data centres in France, out of 32 globally.

Founded by Klaba in 1999, OVHcloud is the biggest European-based cloud services provider, competing against U.S. giants Amazon Web Services, Microsoft’s Azure and Google Cloud, which dominate the market.

French politicians have championed OVHcloud as a possible alternative to U.S. cloud services providers, but it has so far lacked the scale and financial clout to dent their market share.

Klaba said the fire was over and that all employees were safe.