Rick Rescorla was a former British Army patratrooper, a United States Army officer, a former police officer in Northern Rhodesia, and a Vietnam war veteran. At the time of the 9/11 attacks he was the Director of Security for Morgan Stanley at the World Trade Center in the South Tower.
Rescoria, who was of British origin, had anticipated such an attack happening on the twin towers and had used to expertise plan ahead for an evacuation. His evacuation procedures are credited with saving a lot of lives on the day. When the North Tower was hit Rescoria ignored a Port Authority announcement for those in the South Tower to to stay at their desks and instead grabbed his bullhorn, a cell phone, and a walkie-talkie and then organised an evacuation of Morgan Stanley employees. After evacuating most of Morgan Stanley’s 2687 employees he went back up the tower to ensure that everybody had been evacuated, and was in the building when the tower collapsed. His remains were never found.
The Man Who Predicted 9/11 is a 2005 documentary which was shown in the US on the History Channel and in the UK on Channel 4 which tells the story of how he was responsible for saving thousands of lives and selflessly lost his whilst trying to save others.