A senior government official revealed details of the deadly attack on the U.S. Consulate in Benghazi, Libya, September 11, 2012, that killed four State Department officials and wounded three others.



On September 12, President Barack Obama, Secretary of State Hillary Rodham Clinton and Defense Secretary Leon E. Panetta all condemned the attack and the senseless deaths of Americans, and extended their deepest sympathies to the families and colleagues of those who were killed and wounded in Benghazi.



During a teleconference given on background to reporters, the official described the scene of an attack whose elements are unclear or unknown but that killed U.S. Ambassador J. Christopher Stevens, Foreign Service information management officer Sean Smith and two others whose names are being withheld until State Department officials notify their families. Three other Americans were wounded in the attack.



All Benghazi consulate personnel have been evacuated to the U.S. Embassy in Tripoli in a series of flights that included the three wounded personnel and the remains of the fallen State Department officials, the official said.



The Benghazi consulate staff will be transported to Germany, she said.



"The staff that is well is going to stay in Europe on standby while we assess the security situation," she said. "The wounded will be treated [at the Landstuhl Regional Medical Center] in Germany, and the remains will come home."



In the meantime, the official said, "we have taken our embassy in Tripoli down to emergency staffing levels and … we have requested increased support from the Libyans while we assess the security situation."



Last night, she said, State Department officials ordered all diplomatic posts around the world to review their security posture and to take all necessary steps to enhance that posture.



During the briefing, warning that details may change as the attack is investigated, the official offered a timeline of events surrounding the attack.



The consulate in Benghazi is an interim facility acquired before the fall of Libyan dictator Muammar Qadhafi. It consists of a main building, several ancillary buildings, and an annex a little further away, she said.



"At about 4 p.m. Eastern Daylight Time yesterday, which was about 10 p.m. in Libya, the compound … in Benghazi began taking fire from unidentified Libyan extremists. By about 4:15 p.m. attackers gained access to the compound and began firing into the main building, setting it on fire," she said, "and the Libyan guard force and mission security personnel responded."



At the time, three people were inside the building -- Ambassador Stevens, a regional security officer, and Smith -- and while trying to evacuate they became separated by heavy, dark smoke.



"The regional security officer made it outside and then he and other security personnel returned into the burning building in an attempt to rescue Chris and Sean," the official said.



They found Smith, who had died, and pulled him from the building. They were unable to locate Stevens before fire, smoke and small-arms fire drove them from the building, the official said.



"At about 4:45 p.m. Washington time, U.S. security personnel assigned to the mission annex tried to regain the main building but that group also took heavy fire and had to return to the mission annex," the official said.



"At about 5:20 p.m.," she added, "Libyan security personnel made another attempt and that time were able to regain and secure the main building."



The rest of the staff were evacuated to the nearby annex, which itself came under fire at around 6 p.m. Washington time and continued under fire for about two hours, she said.



During that ongoing attack, the official said, two more U.S. personnel were killed and two more were wounded.



At about 8:30 p.m. Washington time, or 2 a.m. in Libya, Libyan security forces helped regain control of the situation, she said.



"At some point in all of this, and frankly we do not know when, we believe that Ambassador Stevens got out of the building and was taken to a hospital in Benghazi," she said, adding, "We do not have any information about his condition at that time. His body was later returned to U.S. personnel at the Benghazi airport."



The official said Stevens made regular and frequent trips to Benghazi to check on developments in the east.



"He had been the secretary's and the president's representative to the Transitional National Council before the fall of Gadhafi and had spent a lot of time in Benghazi and built deep contacts there," she explained. "So this was one of his regular visits."



She said security in Benghazi included a local guard force outside the compound, "which is similar to the way we are postured all over the world. We had a physical perimeter barrier and … a robust American security presence inside the compound, including a strong component of regional security officers."



About the protests, the official said, "We frankly don't have a full picture of what may have been going on outside the compound walls before the firing began [and] … we are not in a position to speak any further to the perpetrators of this attack."



The complex attack will require a full investigation, she added.



"We are committed to working with the Libyans both on the investigation and to ensure that we bring the perpetrators to justice," the official said. "The FBI is already committed to assisting in that but it's just too early to speak to who [the attackers] were and if they might have been otherwise affiliated beyond Libya."



As Clinton said very clearly today, the official added, "We are as committed today as we have ever been to a free and stable Libya that is still in America's interest, and we are going to continue to work very strongly to help them have the future that they want and they deserve."



She added, "I would simply note how quickly and how strongly senior members of the Libyan government came forward to condemn this attack, to offer support to us.



She noted that the consulate's Libyan security forces stood with U.S. security forces in defending the consulate buildings.



"One of the local militias that was friendly to the embassy came to assist as well," the official added, "and I think that really speaks to the relationship that we have built with Libya."



Also here this afternoon, Libyan ambassador to the United States Ali Suleiman Aujali held a press conference to condemn the attack on the Benghazi consulate and the deaths of embassy personnel.



"It is a sad day in my life. I knew Chris personally. He's my tennis partner. He comes to my house. We have breakfast together. I've known him for more than six years. He may be the first American diplomat to [have arrived] in Tripoli … after the revolution. He's very welcomed by the people. He visited the Libyans. He [ate] with them. He [sat] with them," Aujali said.



Aujali also offered his country's "deep condolences" to the American people, to the families, and the president.



"We are very sorry for what happened," Aujali said. "We will do everything possible … to [ensure] that we have better relations, better protection [for] the American diplomats and [for] the international community … working in our country."