- The Marines were sent to verify intelligence reports that Fr. Bossi was spotted. In that scenario, they failed to find any trace of the kidnapped priest.
- They decided to return to base but one of the vehicles in the convoy was got stuck in mud. Thus the entire convoy was stalled, since the ground commander decided to wait for the recovery of the said vehicle.
- The Marines noted the unusual atmosphere in the area and suspected that an ambush was imminent. So they decided to take defensive measures.
- Gun fire erupted between the Marines and what was then unknown elements. And 14 Marines were killed. Later their bodies were found to have been beheaded and mutilated.
In fact initial news stories said that the ambush was perpetrated by Abu Sayyaf.
This assumption only changed when the MILF took responsibility for the ambush, although not the decapitations.
Now, the strange thing is that the MILF, or whoever they are, managed to get at least 200 fighters involved in the ambush in a such short notice. Even if it's their "territory", such a number wouldn't be organized to carry out an ambush.
And another thing. Did the Marines take the same route to and from their mission? If so, why did they not encounter the ambush on their way in? Hmmm...