LINDSEY HILSUM: The last cigarette before heading out. Search and a tank they call it.
The Marines moved through the ruins of Fallujah looking for any gunmen who have not fled or been killed. The most desperate and determined. Tanks rumble in.
The Americans were in this neighborhood the day before. But maybe the insurgents crept back overnight.
The Marines have been told to comb the mosque for weapons, and as they do, the firing starts. It turns into a firefight. The armored vehicle arrives with more ammunition because the houses around the mosque are full of fighters.
A group of Marines is pinned down on a flat rooftop. We're filming from an armored vehicle on the street below. The heavier weapons fire a barrage at the insurgents. They call it "suppressive fire."
A Marine has been injured, and his colleagues need to administer first aid and get him out. A stretcher is brought. This is a serious casualty, and it may already be too late.
But the rest of the group now needs to get out, too under intense fire. This is the most dangerous engagement India company's had in Fallujah.
SOLDIER: We got a medivac coming on!
LINDSEY HILSUM: We weren't allowed to film the casualties. This one was loaded into the truck and taken away. The fire team crosses the street.
SOLDIER: Get on the roof!
LINDSEY HILSUM: They're going to hit the insurgents with an anti- tank missile.
SOLDIER: What's going to happen. M-16's, 240. We're going to pop up, we're going to do five seconds of suppression, alright?
Slow an M-16, like two bursts. That way, it's going to show me where the fire is coming from and I can look at the building. All right? You and you. Ready? Go!
LINDSEY HILSUM: The heavy fire keeps the insurgents' heads down. The tracer has shown the man with the missile the target.
SOLDIER: We're going to use that. Okay?
SOLDIER: We're aiming in that window...
SOLDIER: Aim it right there.
SOLDIER: ...Looks like a doorway.
LINDSEY HILSUM: The back-blast from the missile engulfs everyone in dust. They call in an air strike and the troops must quickly leave the danger area.
SOLDIER: All right, start with the guns. Guns will go first.
LINDSEY HILSUM: They rush down the stairs to find a new position. Fearing the insurgents may still be active, they run down the street.
The debris of the day's battle lies in their path; a rocket launcher, a flattened Kalashnikov. From a safer rooftop, we filmed tanks moving along the street, ready to fire a round into each house where there might still be resistance.
CAPT. BRIAN CHONTOSH, U.S. Marines: There's probably a good twenty or thirty down in that last corner. They're pinched. The whole division has got them surrounded.
They've been using this mosque to treat their wounded, so inside that mosque it's all dirty and this last strip of houses down to our front about 300 meters just full of them, gunshot wounds and stuff trying to get them treated.
They don't want to give up. We tried talking to them with our interpreter, getting them to surrender, walk out on street. They're telling us they'd rather die than come out and surrender so they're going to die.
LINDSEY HILSUM: The Marines begin to relax; the clash is nearing its end. They've made a tactical withdrawal to this rooftop here, waiting for air power to come in and bomb the remaining insurgents. They think there's at least another half dozen still in there.
SOLDIER: Five seconds!
LINDSEY HILSUM: Night is falling, as the Marines go on foot to see if the combined power of all their weaponry has destroyed their enemies.
SOLDIER: Check out the bodies, sir.
LINDSEY HILSUM: In the wreckage of the houses in the street near the mosque, they find the bodies of 21 fighters. According to their documents, these five came from the neighboring town of Ramadi -- terrorists to the Americans, martyrs to those who support their cause.