Parts of the building at the “Le Chalon” sports centre was destroyed by the blast, which occurred shortly after midnight, Xinhua reported.
The deceased victim is a man in his forties, said emergency services spokesman Michel Mean. The two seriously injured have been transported to different hospitals.
For now, the cause of the explosion is still undetermined.
“The building is not supplied by mains gas. Bottles were found on site, but for now, we do not have evidence to determine the cause of the accident,” Mean said.