this is the bustling city of abbottabad, pakistan. from overhead, you can still see the scar in the landscape. this vacant lot-- where boys now play cricket-- is where osama bin laden's home once stood, and where the world's most wanted terrorist hid until the evening of may 1, 2011. >> president obama: tonight, i can report to the american people, and to the world, that the united states has conducted an operation that killed osama bin laden. >> alfonsi: the operation, called neptune spear, took 30 minutes. but then, one seal alerted command that they'd found a ton of computers and electronics and needed more time. the seals were granted ten more minutes, that stretched into 18. they grabbed computers, v.h.s. tapes, books, thumb drives, hard drives and notebooks, carrying them out in bags strung around their neck. how important was that last- minute decision by the seal team to take those documents? >> nelly lahoud: bin laden's greatest fear was about exposing al-qaeda's secrets. and so, the fact that the seals decided to recover the