Ambassador Christopher Stevens was in Benghazi that day to meet with officials over the hunt for ousted dictator Moammar Ghadafi's weapons stockpiles and to open a cultural center. Here is how events played out that day (all times local):
An alert is sent to the CIA security team at an annex about a mile away, the State Department and the U.S. Embassy in Tripoli. Stevens calls deputy mission chief Gregory Hicks at the embassy and tells him, "Greg, we're under attack."
Exclusive: Dozens of CIA operatives on the ground during Benghazi attack
10:30 p.m.: Stevens and Smith have taken refuge behind a fortified door with heavy metal bars that keeps the attackers from breaking in, but they set fire to the villa with diesel fuel. Within minutes, Stevens and Smith are overwhelmed by smoke.
At about the same time, six U.S. security agents leave the CIA annex for the main building. They and 16 Libyan security guards regain control over the compound and start searching for Stevens and Smith.
Shortly after 11 p.m.: A U.S. surveillance drone arrives over Benghazi. Then-Defense Secretary Leon Panetta and Joint Chiefs Chairman Martin Dempsey meet with President Barack Obama.
12:07 a.m., September 12: The State Department sends an e-mail to the White House, the Pentagon and the FBI indicating the Islamic militant group Ansar al-Sharia claimed credit for the attack.
1:15 a.m.: A rescue team from Tripoli arrives in Benghazi. About 30 Americans have been rescued from the consulate building and are holed up with the Stevens at the CIA annex.
2 a.m.: Hicks informs Secretary of State Hillary Clinton that they need to evacuate all Americans from Benghazi. At about the same time, an eyewitness captures on video Stevens being pulled from the smoke-filled building.
4 a.m.: The attackers launch a full-on assault against the annex, dropping mortars on the roof. Navy SEALs Glen Doherty and Tyrone Woods are killed in the attack.
10 a.m.: The bodies of Stevens, Smith, Doherty and Woods are put on the last plane out of Benghazi.