In this Monday, April 11, 2011 file photo, U.S. envoy Chris Stevens, center, accompanied by British envoy Christopher Prentice, left, speaks to Council member for Misrata Dr. Suleiman Fortia, right, at the Tibesty Hotel where an African Union delegation was meeting with opposition leaders in Benghazi, Libya. Libyan officials say the U.S. ambassador and three other Americans have been killed in an attack on the U.S. consulate in the eastern city of Benghazi by protesters angry over a film that ridiculed Islam's Prophet Muhammad. The officials say Ambassador Chris Stevens was killed Tuesday night when he and a group of embassy employees went to the consulate to try to evacuate staff. The protesters were firing gunshots and rocket propelled grenades.