What was Ambassador Stevens doing in the Benghazi consulate when it caught fire?

I was not going to write any more about the Benghazi Attack since the Administration has finally started to admit that the press was correct but I still have one lingering question. What was so important that Ambassador Stevens and his intelligence officer had to be in the consulate when it caught fire? This looks like an avoidable mistake. According to the NYTimes a significant portion of the staff was either employed by the CIA or working for them at gathering intelligence about the local militias and their post revolution transformations. Even if the information was very sensitive I am still confused why the Ambassador needed to personally supervise the document destruction. Surely they had a plan for when and how to destroy the sensitive documents without the Ambassador’s involvement?

The attack in Benghazi, Libya, that killed Ambassador J. Christopher Stevens and three other Americans has dealt the Central Intelligence Agency a major setback in its intelligence-gathering efforts at a time of increasing instability in the North African nation.

Attack in Libya Was Major Blow to C.I.A. Efforts – NYTimes.com