The trolley problem is a thought experiment in ethics about a fictional scenario in which an onlooker has the choice to save 5 people in danger of being hit by a trolley, or by throwing a lever, can divert the trolley to kill just 1 person.
In July 2001, just six weeks before the twin towers came down, a 99-year master lease for all the buildings was transferred to (bought by) a guy named Larry Silverstein.