Tuesday's attack by militants on the U.S. consulate in Benghazi was complex, raged for more than four hours, and included multiple attempts to retake the main consulate building, according two senior administration officials who briefed reporters Wednesday afternoon.
Amid the chaos, the whereabouts of Ambassador Chris Stevens, who died in the attacks, remained unknown until the next morning, the officials said.
"We want to make clear that we are still operating within the confusion of first reports. Many of the details of what happened in Benghazi are still unclear," one of the officials said to start the briefing. "The facts could very well change as we get a better understanding."
The officials then proceeded to detail what they said was the U.S. government's current understanding of how the events in Benghazi unfolded. The officials declined to confirm reports that the administration believes the attack was planned in advance, but they described an extensive and complicated effort by well-armed and seemingly well-informed attackers that caught them by surprise.
At about 10 PM local time (4 PM EDT), the compound in Benghazi began taking fire from "unidentified Libyan extremists," the official said. Fifteen minutes later, the assailants had gotten inside the compound and began firing on the main building and setting it on fire.
Although there are usually 25 to 30 people working on the compound, at the time of the initial attack, only three people were inside the main building: Stevens, Foreign Service Officer Sean Smith, and an unidentified State Department regional security officer. They became separated in the thick smoke inside the main consulate building and only the regional security officer was able to get out, the official said.
The regional security officer returned to the building with more security personnel to try to rescue Stevens and Smith.
"At that time they found Sean. He was already dead, and they pulled him from the building" the official said. "They were unable to locate Chris before they were driven from the building by the fire, the smoke, and the continuing small arms fire."
At about 10:45 local time, security personnel assigned to an annex that was part of the compound made another attempt to retake the main consulate building but they took heavy fire and returned the mission annex, the official said.
At about 11:20 local time, they made another attempt to retake the building, this time with the support of Libyan security forces. They did secure it and proceeded to evacuate the remaining embassy personnel to the annex.
Around midnight local time, the annex itself came under attack. The ensuing gun battle lasted for two hours and resulted in the deaths of two more "U.S. personnel" that the officials said were State Department personnel.
With the help of more Libyan security forces, the situation was finally under control by about 2:30 a.m. local time, but the ambassador was nowhere to be found.
"We believe that Ambassador Stevens got out of the building and was taken to a Benghazi hospital. We do not have any information about what his condition was at that time," the official said, adding that he U.S. government doesn't know who brought Stevens to the hospital, only that it wasn't Americans.
Around daybreak Stevens's body was handed over to "U.S. personnel" at the Benghazi airport. All U.S. personnel, including the dead and three wounded, were subsequently evacuated to Tripoli and then sent on to Germany. The wounded will be treated in Germany and the rest will return home.
The Tripoli embassy has been reduced to emergency staffing levels and all diplomatic missions around the world have been directed to review their security procedures, the official said.
A second administration official said that the Pentagon has deployed a Marine Corps fleet anti-terrorism security team (FAST) based out of Europe.
"The mission of this team is to secure the diplomatic security to our embassy in Tripoli and protect U.S. personnel as needed," the official said. The official declined to speculate if U.S. forces would be involved in the hunt for the attackers but said, "The Department of Defense is ready to respond with additional military measures as directed by the president."
The briefing left several questions about the Tuesday attack unanswered. The officials wouldn't speculate about the identity of the attackers or whether the Benghazi attack was connected to an earlier protest at the U.S. Embassy in Cairo during which protesters breached the compound walls.
"It was clearly a complex attack," the official said. "It's too early to speak to who they were and if they might have been otherwise affiliated outside of Libya."
The officials declined to talk about the security situation at the consulate but did said there was a review of security at all diplomatic security arrangements in the context of preparing for the anniversary of the 9/11 attacks.
"At that time, there was no indication and no threat streams to indicate we were inadequately postured [at the Benghazi consulate]," the official said.
The officials said they simply don't know exactly when or how Stevens died and they declined to confirm reports he died from smoke inhalation, pending an autopsy.
The officials could not say whether the attackers were part of the protests outside the embassy walls.
"We frankly don't have a full picture of what may have been going on outside of the compound walls before the firing began," the official said.
One of the officials did have information on the Cairo embassy statement on Tuesday that has become an issue in the presidential campaign.
"That statement was not coordinated with Washington and therefore was taken down," the official said. "My understanding is that was released at noon Cairo time, which was before the protest began."