As the mob was gathering outside, calls were made, emails sent and requests were made for reinforcements. They were denied. These are those stories.
Obama Admin Denied U.S. Diplomats Help in Libya Who Pleaded For Added Security
Obama : Administration told Military to stand down while watching Benghazi Attack (Oct 26, 2012)
Obama Administration Denies CIA in Benghazi Requested Help (10/26/12)
There were several attacks as far back as January 2012. Requests were made at that time for more security. Assistance was denied. Here are some of the documents requesting help by our Benghazi consulate.