The Notre Dame fire on April 15, 2019, was accidental and likely caused either by a poorly extinguished cigarette or an electrical short circuit during renovation work. Despite investigations, the exact cause remains unconfirmed. The fire started in the attic beneath the roof and spread quickly due to the cathedral's flammable wooden roof structure and lack of fire prevention systems such as sprinklers. Firefighters focused on saving the main structure and towers after the spire collapsed. The fire safety system relied mostly on detection and rapid response but had critical flaws, contributing to the extensive damage. Despite the fire, many valuable relics and rose windows were saved, and the stone ceiling largely contained the blaze from damaging the interior more severely. The disaster highlighted negligent safety measures and inadequate oversight during renovation work, which contributed to the fire's outbreak and spread.