The deadly assault on a U.S. diplomatic mission in Libya on Sept. 11 was preceded by a succession of security lapses and misjudgments, compounded by fog-of-battle decisions, that raise questions about whether the scope of the tragedy could have been contained. 
 
 U.S. officials issued alerts and ordered security precautions in neighboring Egypt ahead of protests and violence on Sept. 11, but largely overlooked the possibility of trouble at other diplomatic postings in the region. 
 
 ... ||||| WASHINGTON — The survivors of the assault on the American Mission in Benghazi, Libya , thought they were safe. They had retreated to a villa not far from the main building where the surprise attack had occurred, and a State Department team had arrived to evacuate them. The eruption of violence had ended, and now they were surrounded by friendly Libyan brigades in what seemed to be a dark, uneasy calm. 
 
 A colleague’s body lay on the ground. They had no idea where their boss, Ambassador J. Christopher Stevens, was, nor how in the confusion he had become separated from his bodyguard and left behind. 
 
 Then, shortly after 2 a.m. on Sept. 12, just as they were assembling to be taken to the airport, gunfire erupted, followed by the thunderous blasts of falling mortar rounds. Two of the mission’s guards — Tyrone S. Woods and Glen A. Doherty, former members of the Navy SEALs — were killed just outside the villa’s front gate. A mortar round struck the roof of the building where the Americans had scrambled for cover. 
 
 The attackers had lain in wait, silently observing as the rescuers, including eight State Department civilians who had just landed at the airport in Benghazi, arrived in large convoys. This second attack was shorter in duration than the first, but more complex and sophisticated. It was an ambush. 
 
 “It was really accurate,” Fathi al-Obeidi, commander of special operations for a militia called Libyan Shield, who was there that night, said of the mortar fire. “The people who were shooting at us knew what they were doing.” 
 
 They also escaped, apparently uninjured. 
 
 Interviews with Libyan witnesses and American officials provide new details on the assault on American diplomatic facilities and the initial moblike attack, set off by a video denigrating the Prophet Muhammad, that transformed into what the Obama administration now, after initial hesitation, describes as a terrorist attack. 
 
 The accounts, which remain incomplete and contradictory, are broadly consistent with what is known about the attack, but they still leave many questions unanswered, including the identity of the attackers and how prepared they might have been to strike at an American target. 
 
 The attack has raised questions about the adequacy of security preparations at the two American compounds in Benghazi. Both were temporary homes in a dangerous, insecure city, and they were never intended to become permanent diplomatic missions with appropriate security features built into them. 
 
 Neither was heavily guarded, and the second house was never intended to be a “safe house,” as initial accounts suggested. At no point were the Marines or other American military personnel involved, contrary to news reports early on. 
 
 Secretary of State Hillary Rodham Clinton announced on Thursday the creation of a review board led by a veteran diplomat and former under secretary of state, Thomas R. Pickering. She also briefed lawmakers behind closed doors on Capitol Hill. But the State Department now faces Congressional demands for an independent investigation of the attacks and any security failures that might have added to the death toll. 
 
 “In my judgment, which is informed by numerous briefings and discussions with experts, the attack in Benghazi was not a black swan,” Senator Susan Collins, Republican of Maine, said at a hearing on Wednesday, “but rather an attack that should have been anticipated, based on the previous attacks against Western targets, the proliferation of dangerous weapons in Libya, the presence of Al Qaeda in that country and the overall threat environment.” 
 
 Investigators and intelligence officials are now focusing on the possibility that the attackers were affiliated with, or possibly members of, Al Qaeda in the Islamic Maghreb — a branch that originated in Algeria — or at least in communication with it before or during the initial attack at the mission and the second one at the mission’s annex, a half-mile away. 
 
 One extremist now under scrutiny is a former detainee at the prison at Guantánamo Bay, Cuba, Abu Sufian Ibrahim Ahmed Hamouda, a Libyan who is a prominent member of an extremist group called Ansar al-Sharia, which some have blamed for the attack. “It is safe to assume that any significant extremist in eastern Libya is going to be under a lot of scrutiny right now,” an American intelligence official said, adding that it was premature to draw any conclusions.
– US officials didn't see the attack on their Benghazi consulate coming—but critics say they should have. There was a slew of terrorist activity in the months before, including a June 6 IED attack on the consulate itself, the Wall Street Journal reports, but Ambassador Chris Stevens kept security to a minimum to show trust in Libya's new government. State Department officials say they were mainly worried about RPG and IED attacks. Given that the June attack harmed no one, one official said, "Our security plan worked." More details about the attack are still coming to light. The New York Times reports today that officials fleeing the consulate took refuge in a nearby villa, where they came under attack again—this time a sophisticated ambush including gun and mortar fire. "It was really accurate," says one Libyan militia member who was there that night. "The people who were shooting at us knew what they were doing." Initial reports called the villa a "safe house," but like the consulate it was never heavily guarded.