Restoration of the 15th century cathedral in the French city of Nantes that was hit by fire last week will take at least 3 years, chief architect Pascal Prunet told a press conference on Wednesday.
The fire on Saturday blew out stained glass windows and destroyed the grand organ, while officials said they suspected arson.
Experts are in the middle of carrying out a study of the exact damage that has been done. Local authorities said it was too early to say how much the restoration would cost.
The fire came just over a year after a massive fire at the Notre-Dame Cathedral in Paris, which destroyed its roof and main spire.
