the architect of 9/11 had eluded the world s most powerful nation for more than a decade. the trail was quite cold. reporter: former cy director michael hayden recalls the early misfires. most of what he had looked more likele elvis sightings than intelligence. reporter: the trail caught fire last august when u.s. intelligence zeroed in on this compound. an unusual compound. unusualle in its security, in its size and location. reporter: its location, just over a mile from pakistan s premier military academy, north of islamabad. the compound was discovered after tracking down bin laden s trusted courier. one of my sources said to me, you know, one of the reasons it was so interesting to us is we knew bin laden was in the construction business. and this was well constructed.
s.e.a.l.s would rather die than be captured. at the end of the day it was a leap of faith. vi . reporter: friday, april 29, just after 8:20 a.m., the mission begins. the president gives the go. the president, after a long night s sleep, basically came in and immediately told the staff, you ve got the green light. let s go. reporter: as president obama departs for the tornado-ravaged south, the u.s. military s best-kept secret is under way. the troops were ready and in place. the equipment was ready to go. the plan had been practiced again and again and again. reporter: america s most wanted man may finally be in reach. osama bin laden. the architect of 9/11 had eluded the world s most powerful nation for more than a decade. the trail was quite cold. reporter: former cy director michael hayden recalls the early misfires. most of what he had looked more likele elvis sightings than intelligence. reporter: the trail caught fire last august when u.s. intell