Some Gone With the Wind trivia:

The famous scene of the fleeing of Atlanta with the towering inferno was actually the studio burning the set of King Kong’s giant wall. They used two stand ins to run across at a distance. You can also see the actress covering her face, not to protect herself, but to disguise the fact they hadn’t yet cast the role of Scarlett so she was protecting the integrity of the film at that point too. Not a scene they could easily reproduce.