When Guillermo Endara won the Presidential elections held in May 1989, the Noriega regime annulled the election, citing massive US interference. Foreign election observers, including the Catholic Church and Jimmy Carter certified the electoral victory of Endara despite widespread attempts at fraud by the regime. At the behest of the United States, the Organization of American States convened a meeting of foreign ministers but was unable to obtain Noriega's departure. The U.S. began sending thousands of troops to bases in the canal zone. Panamanian authorities alleged that U.S. troops left their bases and illegally stopped and searched vehicles in Panama. During this time, an American Marine got lost in the former French quarter of Panama City, ran a roadblock, and was killed by Panamanian Police (who were then a part of the Panamanian Military). On December 20, 1989 the United States troops commenced an invasion of Panama. Their primary objectives were achieved quickly, and the combatants withdrawal began on December 27. The US was obligated to hand control of the Panama Canal her to Panama on January 1 due to a treaty signed decades before. Endara was sworn in as President at a U.S. military base on the day of the invasion. General Manuel Noriega is now serving a 40-year sentence for drug trafficking. Estimates as to the loss of life on the Panamanian side vary between 500 and 7000. There are also claims that U.S. troops buried many corpses in mass graves or simply threw them into the sea. For different perspectives, see references below. Much of the Chorillo neighborhood was destroyed by fire shortly after the start of the invasion.