A hearth at the cathedral in the French town of Nantes is believed to have been begun deliberately, prosecutors say.
3 fires ended up began at the web site and an investigation into suspected arson is under way, Prosecutor Pierre Sennes said.
The blaze wrecked stained glass home windows and the grand organ at the Saint-Pierre-et-Saint-Paul cathedral, which dates from the 15th Century.
It will come a 12 months following the devastating fire at Notre-Dame cathedral in Paris.
But the regional fireplace main mentioned the fire in Nantes had been contained and was “not a Notre-Dame scenario”.
“The damage is concentrated on the organ, which seems to be absolutely destroyed. The system it is located on is extremely unstable and threats collapsing,” Laurent Ferlay told reporters.
The cathedral roof had not been touched by the blaze, he explained.
President Emmanuel Macron has reacted, tweeting: “After Notre-Dame, the St Peter and St. Paul Cathedral is in flames. Help to the firemen who are using all the dangers to conserve the Gothic jewel.”
The French fireplace support tweeted footage of the blaze.
The fireplace commenced in the early morning, with enormous flames obvious from outdoors the creating. Additional than 100 firefighters introduced it underneath handle just after many hrs.
Mr Sennes claimed the national law enforcement would be associated in the investigation and a fireplace qualified was travelling to Nantes
“When we arrive at a location the place a fireplace has taken location, when you see a few different fireplace outbreaks, it is a concern of widespread feeling, you open up an investigation,” he explained.
Newsagent Jean-Yves Burban mentioned he listened to a bang at about 07:30 local time (05:30 GMT) and noticed flames when he went out to see what was going on.
“I am shook up for the reason that I have been here 8 yrs and I see the cathedral every early morning and night. It’s our cathedral and I’ve acquired tears in my eyes,” he advised Reuters.
This is not the initial fireplace at the cathedral. It was destroyed by Allied bombing in 1944, during Entire world War Two, and then in 1972 its roof was mostly ruined.
It was rebuilt 13 many years afterwards with a concrete framework replacing the picket roof.