Launch a full investigation into the President and his roll in the deaths of our Americans in Benghazi

We need to fully investigate the President and his roll in the murders of our Americans in Benghazi, and why they were not given full protection, knowing that September 11 is an anniversary day for terror attacks. When they requested additional security, why was it denied, however, their danger pay was increased. If the government knew it was dangerous enough to give them additional money for that danger, why was their request for security denied? How was it that the government received credible intel during the weeks before September 11, 2012, but it was ignored?
How was it, that our men were under fire, and their request was STILL denied, as the government watched?
How is it that having watched, the President came out and said they weren't sure about it being a planned terror attack?