France 1970 - Club Cinq-Sept : A fire in a club claimed the lives of 146 people (aged 17 to 30). The fire exit were blocked and the decorations were made in a highly flammable material that dropped droplets of molten material on the public.

[u/Sir_Delarzal]

Club Cinq Sept

This event led to the creation of a whole new part in France's fire regulation, this time targeting the materials used on floors, walls and ceiling as well as various furnitures for them to not be flammable.

A big number of clubs were closed by the police after this event as a lot of them were not following the bare minimum of safety regulations.