At 9:40 PM, September 11, 2012, members of Ansar al-Sharia attacked the American diplomatic compound in Benghazi resulting in the deaths of U.S. Ambassador to Libya J. Christopher Stevens and U.S. Foreign Service Information Management Officer Sean Smith. At around 4:00 AM on September 12, the group launched a mortar attack against a CIA annex approximately one mile away, killing CIA contractors Tyrone S. Woods and Glen Doherty and wounding ten others. At the behest of the CIA, top U.S. officials initially described the attacks as the results of a spontaneous protest triggered by recently released anti-Muslim video, Innocence of Muslims. Subsequent investigations showed that while the attack likely was in retaliation for the video, it was premeditated - although rioters and looters not acting with the group may have later joined in after the attacks begun. Stevens was the first U.S. Ambassador killed in the line of duty since 1979.