Hilary Clinton US Secretary of State Hillary Clinton on Wednesday condemned "in the strongest terms this senseless act of violence" that resulted in the killing of American Ambassador Christopher Stevens in Libya. She appeared at the State Department shortly before President Obama is to address the tragedy as well at the White House. Earlier, Republican Mitt Romney had criticized the White House for it's handling of the situation. The Americans were targeted in an attack in their car, trying to move to a safer venue away from the violent protests that erupted at the U.S. Consulate, Reuters reported . Stevens died of suffocation, while the three other personnel were killed by gunshot wounds, CBS News reports.