We don't really know the answer, Politico reports:
The consulate where the American ambassador to Libya was killed on Tuesday is an “interim facility” not protected by the contingent of Marines that safeguards embassies, POLITICO has learned.
Ambassador Chris Stevens was killed with three other Americans in an attack on the U.S. consulate in the city of Benghazi, where Libyan rebels ousted strongman Moammar Qadhafi last year.
Marine Corps spokeswoman Capt. Kendra Motz said that Marines were not posted to the consulate, unlike the embassy in the capital, Tripoli.
A defense official told POLITICO on Wednesday that the Pentagon is sending an elite team of about 50 additional Marines, called a Fleet Antiterrorism Security Team, to reinforce the embassy.
A senior administration official Wednesday called the Benghazi consulate “an interim facility,” which the State Department began using “before the fall of Qadhafi.” It was staffed Tuesday by Libyan and State Department security officers. The consulate came under fire from heavy machine guns and rocket-propelled grenades at about 10 p.m. local time on Tuesday. By the time the attack ended several hours later, four Americans were dead and three others had been injured.