It has been estimated that at least 50 people survived the attack due to the rescue efforts of De Martini and his colleagues. When they arrived on the 89th floor De Martini directed Mak Hanna to carry an elderly man, who could not descend 89 floors, down to safety. De Martini, Ortiz, Negron and da Costa all perished when the North Tower collapsed at 10:28 A.M. Hanna was the only one of their crew to survive.