PARIS: Firefighters doused the smouldering ruins of Notre-Dame with water on Tuesday, the morning after a raging inferno swept through the Gothic cathedral in the heart of Paris as investigators tried to establish what started the fire.Hundreds of firemen battled the blaze which consumed the roof and collapsed the eight-centuries-old cathedral’s spire for more than eight hours before bringing it under control, saving its bell towers and outer walls. Pockets of fire continued to burn inside the building and thorough checks on the cathedral’s structural soundness would be needed, junior interior minister Laurent Nunez said. The Paris prosecutor’s office said it had launched an inquiry into the fire. Several police sources said they were working on the assumption for now that the fire was accidental. “It’s a symbol of our country that risked being destroyed,” Culture Minister Franck Riester told CNews television. Firefighters who entered the burning cathedral saved many of its treasures, Riester said, although some paintings remained inside and risked smoke and water damage. The fire tore through the cathedral’s timbered roofing, where workmen were carrying out extensive renovations to collapsed balustrades and crumbling gargoyles and the spire’s wooden frame. Hundreds of stunned onlookers lined the banks of the Seine river as the fire raged, reciting prayers and singing liturgical music in harmonies late into the night as they stood vigil.