US Ambassador Killed in Consulate Attack in Libya A mob enraged by a film ridiculing Islam's prophet killed the U.S. ambassador to Libya and three other Americans in a fiery attack on the U.S. Consulate in Benghazi. President Barack Obama strongly condemned the violence, vowed Wednesday to bring the killers to justice and tightened security at diplomatic posts around the world. The attack that killed Ambassador Chris Stevens - the first U.S. diplomat to die in the line of duty since 1979 - came on Tuesday's 11th anniversary of the Sept. 11 terrorist strike and presented a new foreign policy crisis for the United States in a region trying to recover from months of upheaval. Libya's interim president, Mohammed el-Megarif, apologized for what he called the "cowardly" assault on the consulate, which also killed several Libyan security guards in the eastern city. Violence also flared in Egypt, where crowds protesting the film at the U.S. Embassy in Cairo climbed its walls and tore down an American flag, which they replaced briefly with a black, Islamist flag. The protests weree touched off by an obscure movie made in the United States by a filmmaker who calls Islam a "cancer." Video excerpts posted on YouTube depict the Prophet Muhammad as a fraud, a womanizer and a madman in an overtly ridiculing way, showing him having sex and calling for massacres. Details of the attack in Benghazi were still emerging Wednesday. Stevens, 52, died as he and a group of embassy employees went to the consulate to try to evacuate staff when hundreds of people attacked with machine guns and rocket-propelled grenades. By the end of the assault, much of the building was burned out and trashed. Dr. Ziad Abu Zeid, who treated Stevens, told The Associated Press that he died of asphyxiation, apparently from smoke. In a sign of the chaos during the attack, Stevens was brought by Libyans to the Benghazi Medical Center with no other Americans, and no one at the facility knew who he was, Abu Zeid said. Stevens was practically dead when he arrived before 1 a.m. Wednesday, and "we tried to revive him for an hour and a half, but with no success," Abu Zeid said. The ambassador was bleeding in his stomach because of the asphyxiation but had no other injuries, he said. The State Department identified one of the other Americans killed as Sean Smith, a foreign service information management officer. The identities of the others were being withheld pending notification of next of kin. "I strongly condemn the outrageous attack on our diplomatic facility in Benghazi," Obama said in Washington, adding the four Americans "exemplified America's commitment to freedom, justice, and partnership with nations and people around the globe." Obama ordered increased security to protect American diplomatic personnel around world. "Make no mistake we will work with the Libyan government to bring to justice the killers who attacked our people," he said. Obama added: "We reject all efforts to denigrate the religious beliefs of others, but there is absolutely no justification for this type of senseless violence, none." El-Megarif offered his condolences to the U.S. and also vowed to bring the culprits to justice and maintain his country's close relations with Washington. "We extend our apology to America, the American people and the whole world," el-Megarif said.