Initial reports via the front of the hospital where the wounded were being treated relate that there were incoming Iraqi missles at the same time and it was impossible to tell where the missle came from that hit the convoy, however later reports (still in the field, nothing confirmed by eyewitness reports or any investigation of the scene) say that Special Forces working with the Kurdish fighters in the North called in an air strike to take out advancing Iraqi tanks and it appeared as if one of the bombs dropped landed on the convoy instead (they were close enough to the tanks to be under the fire of the tank's missles).
Unfortunate to say the least, esp with the advanced technology the fighter planes use and the capability they have to be precise in their targets.
Still, nothing is "official" since there has not yet been any on-site investigation short of the wounded getting themselves and their commrades out of harm's way and to the hospital and "confusing" was commonly used to describe the whole scene.
I would imagine that if these forces mean anything to the coalition, that they will have 15 hr per flight air protection (constant air to ground recon), the same as the Marines in and around Baghdad...let's hope so anyway.