French Prime Minister Édouard Philippe on Wednesday announced an international architects’ competition to rebuild the spire of Notre Dame Cathedral, reported BBC. A massive fire engulfed the historic cathedral in Paris on Monday while renovation work was under way. The cathedral’s spire collapsed under the fire.

Philippe said the competition would give the 850-year-old building “a spire suited to the techniques and challenges of our time”. The spire was added to the cathedral during a 19th Century restoration project led by architect Eugène Viollet-le-Duc.

“The international competition will allow us to ask the question of whether we should even recreate the spire as it was conceived by Viollet-le-Duc,” said Philippe, according to The Guardian. “Or, as is often the case in the evolution of heritage, whether we should endow Notre Dame with a new spire. This is obviously a huge challenge, a historic responsibility.”

Several people, including billionaires, have so far raised €880m (approximately Rs 6,896 crore) to restore the Unesco heritage site. Prime Minister Philippe said the government would present a bill next week to ensure “transparency and good management” during the reconstruction project.

French President Emmanuel Macron had on Tuesday promised to rebuild the cathedral within five years. However, experts have expressed their doubts about the time span. French conservation architect Pierluigi Pericolo said it was “a colossal task” that would take “no less than 15 years”.

Companies are also worried about the lack of skilled workers. “We’ll have to recruit 100 masons, 150 woodworkers and 200 roofers,” said Jean-Claude Bellanger of the artisans’ organisation the Compagnons du Devoir. “…We have the firms and the expertise, but there’s a serious lack of young people for this work.”