[amom]

"...Officials now say tragedy was only averted on Northwest flight 253 because a makeshift detonator failed to work properly.

Bomb experts say there was more than enough explosive to bring down the Northwest jet, which had nearly 300 people aboard, had the detonator not failed, ..."

http://www.jihadwatch.org/2009/12/report-flight-253-bomb-built-by-al-qaeda-in-yemen-flight-saved-by-failed-detonator.html

[amom]

more from the Jihad Watch link.

"...contained more than 80 grams of PETN...sewn into Abdulmutallab's underwear..."