ABC is reporting that the FBI on scene investigating the explosion have found remains at the site of the explosion which indicate that a suicide bomber was involved. Nothing other than that at this time. Since there were U.S. military, U.S. civilians, and Iraqi military in the tent at the time, the theory seems to be an infiltrator in the Iraqi security forces.
What about a secondary explosion from either our troops (via live ammo or grenades) or cached explosives. Initial reports has three explosions. Do troops come into the mess-hall armed?