multiple bombings in the new york city subway system. zazi had received terror training in an al qaeda camp. he pleads guilty. later that year, on christmas day, umar farouk abdulmutallab unsuccessfully attempts to detonate plastic explosives hidden in his underwear on a flight from amsterdam to detroit. he's apprehended, pleads guilty, and is sentenced to life in prison. times square, the heart of new york city -- in 2010, 30-year-old pakistani american faisal shahzad attempts to detonate an improvised bomb inside his parked nissan pathfinder. the crude device fails to explode and shahzad was apprehended days later. one attack is successful and causes multiple u.s. casualties, the largest u.s. military facility in the world, ft. hood in texas, is the site of a mass shooting by u.s. army psychiatrist, nidal malik hasan, a u.s. citizen. in touch with al qaeda linked clerics online but not formally