Paris' Notre-Dame restoration: the challenge of rebuilding a 'forest' of oak beams

April 15th, 2019: the Notre-Dame Cathedral in Paris, a beacon of Gothic architecture, is hit by a devastating fire. Spectators in France and abroad watched aghast as the forest of oak beams and the iconic spire collapsed in what felt like an interminable blaze. Once the fire passed with the worst arguably avoided, the focus fell on its restoration. One challenge was rebuilding the so called "forest" of centuries old oak beams.