An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to the death toll being so high. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail which proved so deadly. What was it?

Trivia Riddle

The doors at 'The Coconut Grove' opened inward. In the mad panic to escape the fire, people were crushed against the doors and could not pull them open. After 'The Coconut Grove' disaster in 1942, all public buildings had to have doors which opened outward.