The annex in Benghazi to which U.S. diplomatic personnel were evacuated was a CIA base that the agency had established as its first stronghold in Libya before autocrat Moammar Gaddafi was overthrown late last year.
U.S. officials said the CIA base learned of the assault on the nearby diplomatic compound in a desperate phone call about 9:40 p.m.
CIA security operatives assembled their gear and lined up vehicles even while agency officials sought, without success, to enlist Libyan militias that had been hired to provide security for the diplomatic outpost in Benghazi.
“Over the next 25 minutes, team members approach the compound, attempt to secure heavy weapons” from Libyans encountered along the way and “make their way onto the compound itself in the face of enemy fire,” the senior U.S. intelligence official said.
Shortly after 11 p.m., an unarmed Predator drone diverted from another mission arrived over Benghazi and began providing video surveillance.
The CIA operatives appear to have been part of a broader group of U.S. security personnel and Libyan guards who made several attempts to fight their way into a structure known as “Villa C,” which served as the safe house and the VIP residence for the mission, and where Stevens had taken cover. Each time, the would-be rescuers were forced to retreat from heavy smoke and flames that had engulfed the structure.
By 11:30 p.m., “all U.S. personnel, except for the missing U.S. ambassador, depart the mission,” the U.S. intelligence official said. “The exiting vehicles come under fire.”
By then, attackers had also descended on the CIA compound, about a mile from the diplomatic facility. The “annex,” as the CIA base was known in internal documents, continued to come under small-arms and rocket fire sporadically over the next 90 minutes.
Then, about 1 a.m., the siege went suddenly quiet, a pause that would last until near
daybreak, apparently leading CIA and State Department officials to think that the danger had passed.
In the “pre-dawn time frame, that team at the airport finally manages to secure transportation and armed escort and — having learned that the ambassador was almost certainly dead — heads to the annex to assist with the evacuation,” the official said.
The team arrived, accompanied by Libyan security elements, at 5:15 a.m., “just before the mortar rounds begin to hit the annex,” the official said. Other accounts have suggested that multiple mortars were aimed at the site, initially missing their target before striking the roof, where guards had taken position and were returning fire.
Two CIA contractors, both former Navy SEALs, were killed: Tyrone Woods, a security officer based in Benghazi, and Glen Doherty, who was part of the team rushed by air from Tripoli.
That final spasm of violence lasted 11 minutes, officials said. “Less than an hour later, a heavily-armed Libyan military unit arrived to help evacuate the compound of all U.S. personnel,” the senior U.S. intelligence official said.
The account, though the most comprehensive to date, still leaves a number of questions unresolved. Among them are why the single Predator overhead was unarmed and whether a model equipped with Hellfire missiles might have been able to strike the mortar launching site used by the attackers or otherwise disrupt the assault.
Another question is why “a heavily-armed Libyan military unit” was able to arrive at the annex around sunrise but was not available earlier despite presumably frantic U.S. calls.
Julie Tate contributed to this report.