The U.S. government tightened airline security as it searches for answers to how a 23-year-old Nigerian man eluded extensive systems intended to prevent attacks like his botched Christmas Day effort to blow up a Northwest flight from overseas.
Umar Farouk Abdulmutallab, who claimed ties to Al Qaeda, was charged Saturday with trying to destroy a Detroit-bound airliner, just a month after his father warned U.S. officials of concerns about his son's religious beliefs.