correspondent richard engel is in syria. he joins us live. richard, what can you tell us about this attack? >> reporter: so, we're learning more about what u.s. forces were doing when this explosion took place. multiple local residents and -- among them witnesses say that u.s. forces had been on a patrol in the area, and that they would routinely stop at this restaurant, either going in to eat or to pickup food that's correct they would go to this same restaurant, one of only two, a kurdish commander said, that u.s. forces in the area would go to, and that they were there today at 1:00 right around lunch time. that some u.s. forces were inside the restaurant, others were outside talking to locals, presumably guarding the door, when a man in civilian clothing walked in, got right into the doorway itself, and exploded a