ABBOTTABAD, Pakistan (AP) - Under powerful floodlights and surrounded by rings of soldiers and police, heavy machines began Saturday night to demolish the three-story compound in northwestern Pakistan where Osama bin Laden lived for years and was killed by U.S. commandos last May. Each blow helped eliminate a concrete reminder of the painful and embarrassing chapter in Pakistan's history that the al-Qaida chief's discovery and death in a town not far from the nation's capital represented. Pakistan was outraged by the covert American raid in Abbottabad because it was not told about it beforehand - a decision the U.S. explained was driven by concerns that someone in the government might tip off bin Laden. The terror leader's death was cheered across the globe, but many Pakistanis were angry that the U.S. violated its territory and that its troops were powerless to stop American soldiers from attacking a compound located next to the country's equivalent of West Point, the elite U.S. military academy. Just as U.S. Navy SEALs waited for the cover of darkness to descend on bin Laden's compound by helicopter from neighboring Afghanistan, Pakistani authorities held off on tearing it down Saturday until the sun had set, said local residents. They brought in at least three machines equipped with powerful crane-like arms during the afternoon and also set up floodlights that allowed them to begin work at night, said the residents, who spoke on condition of anonymity because they were afraid of being harassed by the government. A large team of police set up an outer cordon around the compound to keep spectators and journalists away, said an Associated Press reporter who managed to get close enough to see the demolition work under way. The bulldozers broke through tall outer boundary walls that ringed a courtyard where one of the U.S. helicopters crashed during the operation to kill bin Laden. The government did not give advance warning that it planned to tear down the compound. But the U.S. has not found any evidence that senior Pakistani officials knew of the al-Qaida chief's whereabouts. The raid, which lasted around 40 minutes, was a serious blow to the already troubled U.S.-Pakistan relationship. Pakistan responded by kicking out more than 100 U.S. troops training Pakistanis in counterterrorism operations and reduced the level of intelligence cooperation. Some members of Congress called on the U.S. to cut of the billions of dollars of military and civilian aid to Pakistan unless Islamabad explained bin Laden's presence in Abbottabad and boosted cooperation on the Afghan war. The aid has continued, although at a somewhat lower level. A U.S. official, speaking on condition of anonymity to discuss the classified drone program, denied reports that the drone was shot down. Abbot reported from Islamabad. Associated Press writers Rasool Dawar in Islamabad, Riaz Khan in Peshawar, Pakistan, and Kimberly Dozier in Washington contributed to this report.