PARIS (CBS/AP) - A "computer glitch" may have been behind the fast-spreading fire that ravaged Notre Dame, the cathedral's rector said Friday. Speaking during a meeting of local business owners, rector Patrick Chauvet did not elaborate on the exact nature of the glitch, adding that "we may find out what happened in two or three months."
On Thursday, Paris police investigators said they think an electrical short-circuit most likely caused the fire. French newspaper Le Parisien has reported that a fire alarm went off at Notre Dame shortly after 6 p.m. Monday but a computer bug showed the fire's location in the wrong place.
The paper reported the flames may have started at the bottom of the cathedral's giant spire and may have been caused by an electrical problem in an elevator. Chauvet said there were fire alarms throughout the building, which he described as "well protected."
The fire burned through the network of enormous centuries-old oak beams supporting the monument's vaulted stone ceiling, dangerously weakening the building. The surrounding neighborhood was blocked off as stones continued to tumble off the sides of the cathedral after the devastating blaze.
A fire brigade spokesman said Friday architects and construction workers have stabilized the damaged structure and firefighters would leave the site Friday night. "There is no more risk the edifice's walls could fall down," Lt. Col. Gabriel Plus told The Associated Press, adding that firefighters have been able to cool down the walls and debris from the roof inside the cathedral.
"It's a miracle that the cathedral is still standing, and that all the relics were saved," he said. Charlotte Hubert, president of a group of French architects who specialize in historic monuments, told BFM television that experts plan to spread a custom-made peaked tarpaulin across the cathedral's roof, with enough space to also shield workers rebuilding the frame.
Chauvet said he wanted a temporary wooden structure to be built to serve as the cathedral as Notre Dame is being rebuilt, BBC News reports. "We mustn't say, 'The cathedral is closed for five years and that's it,'" Chauvet told France's CNews.
Chauvet called for an "ephemeral cathedral" in front of Notre Dame. The wooden structure, Chauvet said, should be "beautiful, symbolic and attractive."
About 50 investigators are involved with the probe. Some 40 people, including those involved in the cathedral's restoration work before the fire, had been questioned by Thursday, according to the Paris prosecutor's office.
Officials had said a fire alarm was triggered at 6:20 p.m., but no fire was discovered. Then, at 6:43 p.m., another alarm sounded.
At that point, fire spread quickly from the roof near the rear of Notre Dame. In less than an hour, it engulfed the spire, which -- just 13 minutes later -- collapsed as onlookers watched in horror.