The French army general in charge of rebuilding fire-ravaged Notre Dame Cathedral in Paris says renovation work will begin in earnest later this year.

Gen. Jean-Louis Georgelin told a French parliament commission Wednesday that workers are still securing the structure. Concerns persist that Notre Dame’s vaulted ceilings could collapse.

“Even if we are rather confident and even if all the indicators seem positive, it is still too early to affirm that the cathedral is saved,” he said.

The April fire destroyed the landmark’s spire and the roof that kept its twin-towered facade and ceilings stable.

In mid-February, specialists plan to start taking down scaffolding that was installed before the fire for planned repair work. The process will take four months and involve professional climbers removing 40,000 pieces of scaffolding weighing a total of 200 tons, Georgelin said.

Read more: AP