Scores of firefighters on Thursday fought a blaze at Paris' Cite des Sciences, one of the biggest science museums in Europe.
Two firefighters were slightly injured before the flames were doused, but there was no damage to museum exhibits, the fire brigade said.
"The fire is completely under control. There is no risk of it spreading," spokesman Gabriel Plus told AFP.
The fire broke out before dawn in a building that was being decorated, and took five hours before being quenched.
Smoke and flames damaged an area of 10,000 square metres (107,000 square feet), ravaging a 110-million-euro ($122 million) scheme to turn the building into an area for shops.
The fire alarm system was not operational because of the work, said Plus.
Around 30 fire trucks and 120 firefighters were sent to the scene. Two fighters were treated after being overcome by intense heat.
The heat was so fierce that firefighting teams were only able to work for 20 minutes at a time before having to be rotated.
Around 50 firefighters remained on the scene by late morning.
The Cite des Sciences is more a science learning centre for the general public than a traditional museum.
Located in northeastern Paris in the Parc de Villette, on the site of the city's former slaughterhouses, the complex draws around five million people a year.
The museum comprises four huge cube-shaped buildings.
The fire occurred in a cube that was being fitted out for shopping.
Called "Vill Up," it was was due to open on October 15.