1911 and 2011 are not drop safe as they do not mitigate the firing pin carrying forward and striking the primer when the gun is dropped. Known issue for a long time with the design of the 1911 and was addressed in the manual of arms. The failure is when the crown of the barrel strikes first. It was deemed acceptable for use as the round was most likely to be discharged when the barrel was pointed at the ground.
Most firearms designed after 1940 are drop safe. The exceptions are the ones that follow the flawed design of the 1911
The sidearm that replaced the 1911 in military service the Beretta 92 was, some say, primarily selected as it was hammer fired and drop safe so as to stay as close to the then current manual of arms and sidearm doctrine.