As a new book by American soldier Jessica Lynch tells the story of her captivity in Iraq and rescue by US special forces, the BBC's Andrew North - who was "embedded" with nearby troops and one of the first reporters on the scene, looks at the little-known side of the operation.
The main highway through eastern Nasiriya is an unremarkable, two-mile stretch of road. Grey, low-built houses on either side, there are no particular landmarks, or sights as you drive along it.
The main road into the city was dubbed "ambush alley"
Only if you look closely at the buildings and see the clusters of bullets holes do you get a clue to what took place here on Sunday 23 March 2003.
It was along this road that the US army convoy carrying Jessica Lynch was ambushed. But a lot more happened that day, in a story that rarely gets told.
Because by the end of that Sunday, 29 American service men and women would be dead, the worst US losses of the Iraq war.
Nasiriya was the scene of bloody close-quarter fighting
I remember first reports of the ambush coming in. Frantic radio traffic. American soldiers caught in heavy Iraqi fire. Several killed, others missing.
Soon after, more reports of casualties, from the US marine battalion sent to help the soldiers. "We got three KIAs confirmed," I heard amid the bursts of static. The numbers kept rising.
I was an embedded reporter with the marines, at their command post just outside Nasiriya at the time. They were part of a unit known as Task Force Tarawa, sent to the city with orders to take bridges.
But their soldier compatriots, among them Private Lynch, had got there first - by mistake.
They were part of the 507th maintenance company, not frontline combat troops. They had taken a wrong turn and instead of bypassing the city, they had ended along that eastern road - which was soon christened 'ambush alley'. As they tried to retrace their steps, the Iraqi Fedayeen militia closed in.
Lightly armed, the Americans stood little chance against these determined paramilitary-style forces, using rocket-propelled-grenades and heavy machine guns.
In the resulting battle, 11 soldiers were killed and five others taken prisoner, in addition to Lynch. But worse was to come.
'Seize the bridges'
The 1st Battalion, 2nd Marine regiment, known as 1/2 marines, who were approaching from the south, were ordered to speed up to try and rescue any survivors. Giant M1 Abrams tanks were sent over the first bridge, across the River Euphrates.
Ten soldiers from the 507th were recovered alive. But as 1/2's commander Lt Col Rick Grabowski said later, "we still had our mission, to seize those bridges." His tanks were now refuelling, but he was under pressure to press on.
However, Iraqi units had used the time since the early morning ambush on Lynch's convoy to bring in reinforcements. The first marines across the Euphrates bridge came under an avalanche of fire.
And inside their more lightly-armoured amphibious assault vehicles, which the marines call 'tracks' they were vulnerable to Iraqi RPGs.
The marines made it through, but then got bogged down tackling Fedayeen fighters in the narrow, muddy streets just off the road. This was not the high-tech, long-distance combat the US military prefers, but bloody, close-quarter fighting.
Many of the Iraqis were dressed in civilian clothes. "Found it hard to work out who the enemy was," said Corporal Josh McCall. "They'd fire at us, then put down their weapon and take off walking like a civilian."
With his Bravo company tied up, Grabowski ordered Charlie company to race north to the northern end of 'ambush alley'. They had to take the second bridge, over the Saddam canal. But there were no M1 tanks available to lead the way.
Out in the open, Charlie company marines found themselves under a devastating Iraqi mortar barrage. Casualties mounted quickly. But then they came under attack from their own side - an American A-10, called in to give air support, opened up with its 30mm cannon.
Several marines are thought to have died in this friendly fire, but details of the Pentagon investigation have still not been released.
The main road into the city was dubbed "ambush alley"
"A marine screamed, 'Come and give me a hand with these bodies'," remembers Charlie company Staff Sergeant Michael Sachim-Smith.
"That's when the reality hit in, once we started seeing the medevacs come in and seeing marines carry bodies off the tracks. Several of them were marines I knew close."
Some of the injured were loaded into undamaged tracks. But as they headed back down the road, Iraqi fighters caught the marines in a volley of fire.
"We started hearing our track taking fire and then a real loud explosion," said Corporal Josh Winshull, a squad leader in Charlie company's 1st platoon.
"The track broke. We ran out and grabbed what wounded we could," Winshull continued. "Had a lot of guys take shrapnel, I took shrapnel. We were taking a lot of RPG and small arms fire. And I saw the burning track behind us and it didn't look like anybody lived through that."
It was one of two vehicles that had been all but vaporised after the grenades dropped through the hatch and detonated the ammunition inside.
It was several weeks before some of the marines inside were identified, through DNA testing on their remains - a grisly reminder of the ferocity of the battle.
But without a vehicle Corporal Winshull, together with the survivors, had to run for cover in a nearby building, in the middle of ambush alley.
There they came under renewed Iraqi attack. They held them off, but their radios were down. With the confusion elsewhere, it was several hours before 1/2 commanders realised they were there and sent a rescue party to retrieve them.
By the end of the day, 1/2 marines had seized both bridges, but 18 of them were dead - all from Charlie company. Scores more were injured. It was the heaviest loss of life for an individual US unit since the Mogadishu debacle of 1993.
But the story of 1/2 marines is seldom heard amid all the focus on Jessica Lynch and her disputed rescue. Some I spoke to after the war expressed their frustration at the way the media had concentrated on the 20-year-old army private.
They don't blame Jessica, but they feel their role has not been given sufficient recognition, especially as they rescued some of the soldiers from her lost convoy.
However, that bloody Sunday was not the end of the story for Nasiriya. The fighting in the city continued for another 10 days. By the time the city was finally under US control, hundreds of Iraqis had been killed and wounded.
When I returned to the city, medical staff in the main hospital - where Jessica Lynch was treated - estimated that over 1,000 Iraqis had died during the fighting. Many were military personnel, but they believe the majority were civilians. Thousands more had been maimed and injured.