Probably one of the closest calls in Hollywood stunt history, Joe Canutt was doubling for Charlton Heston in the chariot race scene when he was thrown from the chariot. Fortunately he managed to grab onto it before being trampled to death and the scene was kept in the final release of the film.
#22, "...engineers had worked out the fall of the facade so that the window would be in just the right spot to miss Buster, but it was far from an exact science and any deviation in the fall of the facade would have probably killed him. Buster, who was dealing with severe depression at the time, was indifferent to the danger." -guitcad1 on youtube