PARIS, April 16 (Xinhua) -- Donations of multi-million euros have been pledged to rebuild the 850-year-old Gothic building Notre Dame Cathedral which was engulfed by a major fire on Monday.

The devastating blaze has been put out after burning for 15 hours, local media reported on Tuesday.

French President Emmanuel Macron has promised to rebuild the cathedral which draws millions of visitors annually.

Two of France's most rich businessmen, Francois-Henri Pinault, chief executive of the Kering group which owns brands including Gucci and Yves Saint Laurent, and Bernard Arnault, the main shareholder of luxury group LVMH, said they would offer donations of 100 million euros (113 million U.S. dollars) and 200 million euros respectively.

"The Arnault family and the LVMH group would like to show their solidarity at this time of national tragedy, and are joining up to help rebuild this extraordinary cathedral, which is a symbol of France, of its heritage and of French unity," Arnault said in statement.

That was followed by a 100-million-euro pledge by energy giant Total and 50 million euros by Paris city hall.

Paris Mayor Anne Hidalgo suggested to organize" in the coming weeks a major conference of international donors" bringing together businessmen from over the world to raise funds necessary to restore Notre Dame Cathedral.

In early Monday evening, a fire broke out in the famed cathedral. Online footage showed thick smoke billowing from the top of the cathedral and huge flames between its two bell towers engulfing the spire and the entire roof which both collapsed later.

According to the official Paris fire service Twitter account, nearly 400 firefighters attended the scene, while "two police officers and a firefighter were slightly injured."

"The cathedral's structure is saved and the main works of art are safe," it said.

Local media reported that the fire, which broke out at around 1645 GMT, may be linked to renovation works.

According to Junior Interior Minister Laurent Nunez, Notre-Dame cathedral is "holding up ok" overall but "Some weaknesses" have been identified in its structure.

Paris public prosecutor Remy Heitz on Tuesday said the blaze at Notre Dame Cathedral was probably caused by accident as no signs "at this stage" pointed to a criminal purpose.

"I say very clearly that nothing at this stage is going in the direction of a voluntary act," Heitz told reporters, adding that they are favoring the theory of an accident.

"At this point, experts can not have access to the site. The investigations are just beginning," he said.

The inquiry to determine how the fire broke out would be "long and complex", he warned, pledging that "all means are implemented to know the truth, to know the origin of this terrible fire." (1 euro = 1.13 U.S. dollar)