A high-ranking U.S. official confirmed Monday that a U.S. drone strike took down al-Qaeda’s “most sophisticated” bomb maker in Yemen in 2017.

Ibrahim al-Asiri, who was the mastermind behind the 2009 plot to take down a jet over Detroit on Christmas Day with an underwear bomb, was killed by the drone in eastern Yemen, according to information from a tribal leader and source linked to al-Qaeda, the Associated Press reported.

“Probably the most sophisticated terrorist bomb maker on the planet. Incredibly creative, incredibly innovative,” former CIA deputy director Michael Morell told CBS News.

Morell added that most Transportation Security Administration (TSA) procedures travelers are familiar with that are currently in use are because of al-Asiri.

“A good chunk of what you have to take out of your bag and what has to be screened is because of Asiri and his capabilities of putting explosives in very difficult to find places,” Morell said.

Al-Asiri reportedly constructed the underwear bomb worn by Umar Farouk Abdulmutallab in his failed attempt to blow up the aircraft. Al-Asiri also took part in a scheme where he hid explosives inside printer cartridges bound for the U.S.