Former Navy SEAL Glen Doherty one of 4 Americans killed in attack on U.S. consulate in Libya (CBS/AP) BOSTON - A former Navy SEAL from a Boston suburb was one of four Americans who died in the attack on the U.S. consulate in Libya Wednesday. Forty-two-year-old Glen Doherty was killed with U.S. Ambassador Christopher Stevens in Benghazi, a family friend told CBS Boston on Thursday. "He was on security detail and he was protecting the ambassador and also helping the wounded"' when he was killed, his sister, Katie Quigly told the Boston Globe. Doherty was a 1988 graduate of Winchester High School. A third victim has been identified as Foreign Service Officer Sean Smith, an Air Force veteran who had worked as an information management officer for 10 years in posts such as Brussels, Baghdad and Pretoria. The identity of the fourth American killed is still not known. The four Americans were killed when a group of U.S. employees went to the consulate to try to evacuate staff as the building came under attack by a mob wielding guns and rocket propelled grenades. Stevens is the first U.S. ambassador to be killed in an attack since 1979, when Ambassador Adolph Dubs was killed in Afghanistan. On Thursday, a senior Libyan security official said the attack was an organized two-part operation by heavily armed militants that included a precisely timed raid on a supposedly secret safe house just as Libyan and U.S. security forces were arriving to rescue evacuated consulate staff. Wanis al-Sharef, eastern Libya's deputy interior minister, said Stevens and another American were killed in the consulate as plainclothes Libyan security were evacuating them to the safe house. The second assault targeted the safe house, killing two Americans and wounding nearly about 30 Libyans and Americans. Meanwhile the Obama administration has begun what appears to be a terrorist hunt in Libya, as evidence mounts that the attack was perpetrated by well-armed thugs and not an out-of-control crowd. One destroyer, the USS Laboon, moved to a position off the coast Wednesday, and the USS McFaul is en route and should be stationed off the coast within days. Officials said the ships, which carry Tomahawk cruise missiles, do not have a specific mission. But they give commanders flexibility to respond to any mission ordered by the president. Three Americans injured in the assault on the consulate in Benghazi were being treated Thursday at the U.S. military hospital in Landstuhl, Germany, near America's Ramstein Air Base, CBS News has learned. The White House says President Obama called the presidents of Libya and Egypt Tuesday and urged them to continue working with the United States to ensure the safety of diplomatic personnel. Mr. Obama thanked Libyan President Mohamed Magariaf for his condolences over the deaths of Stevens and the three other State Department officers. During a second call, Egyptian President Mohammed Morsi promised Egypt "would honor its obligation to ensure the safety of American personnel," the White House said.