officials as the al qaeda figure most determined to attack the u.s. it was under al wuhayshi that al qaeda tried to bring down a series of aircraft with bombs hidden in shoes, underwear, even printer cartridges. they all failed to detonate. but what scared authorities was that each of the devices was able to get past what the u.s. thought was state-of-the-art airport security. >> it's a significant development that he's dead. this is a blow to the al qaeda movement overall. >> reporter: al wuhayshi, who rose from osama bin laden's top aide to number two in al qaeda worldwide, was last seen in this 2014 video from yemen, rallying his fighters in a large, open-air meeting, as if to defy the cia predator drones that flew overhead. and now there is word that the cia drones targeted a second al qaeda leader this one in libya. the leader of the al qaeda group there that took over an oil refinery and killed dozens of hostages, including three americans.