Zacarias Moussaoui pleaded guilty Friday to helping al Qaeda carry out the Sept. 11 hijackings and said he understood he could be put to death for his role in the deadliest terror attack in American history. U.S. District Judge Leonie M. Brinkema accepted the plea, making the French citizen the lone person convicted in a U.S. court for the 2001 attacks that killed nearly 3,000 people. Full Story