failure, high. would rather die than be captured. at the end of the day it was a leap of faith. reporter: friday, april 29th, just after 8:20 a.m., the mission begins. the president gives the go. the president, after a long night s sleep, he basically came in and immediately told his staff you have 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 underway. 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 cia director michael hayden recalls the early misfires. most of what we had looked many more like elvis sightings rather than substantive intelligence. u.s. intelligence zeroed in on this co