Natural News ) Twenty one years ago, terrorists took over US planes and flew them into skyscraper buildings in New York City, shocking the nation and killing at least 3,000 people. Afterwards, most Americans were afraid to board planes, wondering if it would happen to the one they were on. So, the authorities took action to prevent this type of tragedy from happening again. Many US planes featured US marshals aboard to protect the cockpit and the pilots. Flight deck doors were built to keep out terrorists or anyone else who decided to go crazy and try to take over...