So it has come to this. The US First Armoured Division is firing on ambulances and rocketing the homes of the Shia Muslims they came to save from Saddam's oppression, writes Lara Marlowe, in Sadr City
This immense slum in north Baghdad is living up to its reputation as the "city of martyrs". At least 57 Iraqis were killed here by US forces, and 236 others wounded, during the first two nights of this week.
In Shouhada Hospital, Ra'ad Daayer, an ambulance driver, waits for a second operation to repair damage to his internal organs. Mr Daayer says that he was bringing a wounded pregnant woman named Sabiha Lofta to Shouhada when the machine-gunner on top of a US tank opened fire on him, 100 metres from the hospital, at about 9.30 p.m. on Sunday.
The ambulance siren was turned on and its red light was flashing. Mrs Lofta and her unborn infant died. "No one ever fired on ambulances in Iraq before," he says in disbelief.
"Things will get worse and worse," the hospital administrator predicts, standing beside Mr Daayer's bed. "Iraqi people are not monsters. But there is a foreign object in their body, and they want to eject it."
What will happen if the Americans arrest Sheikh Moqtada al-Sadr, the Shia cleric whose supporters are rioting across the country? "A catastrophe," Mr Daayer's visitors reply in unison, then blurt out, one after another: "A massacre all over Iraq . . . It will be open war . . . There will be suicide missions."
Their speculation is interrupted by a wail from two rooms down the hall. A middleaged man, wounded overnight, has died. "Sabri, Sabri, my husband," the woman screams. "Don't leave me, don't leave me."
The US tank which fired on Mr Daayer's ambulance is still hunkered down at an intersection near the hospital. "Silent Killers" is stencilled on one of the tank barrels. Standing in a turret, a GI in battle gear spoons gruel from a foil envelope.
Ahmad Abdul Rida says that most of the 17 people living in his mud-brick house were sleeping when the Apaches fired rockets into the ground and upper floors, wounding four people.
"We were not resisting the Americans. We were just living in our house," his upstairs tenant Haidar Hadi protests, showing me a large hole in the wall.
Nextdoor, the Apaches destroyed the van belonging to Abu Ala'a, the only transport for his family of 14, and Saleh Mansour's pick-up truck. Mansour's sons, Amer and Ra'ad, lie wounded in the front room.
Amer was thrown across the room by the force of the blast, fracturing his knee and ankle. Ra'ad has a contusion the size of an egg next to his eye and a bandaged elbow. When we enter the room, he sits up, weeping. "We treated them at home," says Hassan, a third brother. "Because the Americans shoot at everyone in the streets."
Sadr City grew restive when new US troops rotated in last month. "Before, they asked our permission to drive their tanks on our pavement. Now they are rude," says Hassan Saleh.
Ahmad Abdul Rida can hardly believe it's the same army. "Before, there was even an American officer who came into the café and bought tea for everyone and smoked the narguileh (water pipe)!"
And what about "Mehdi's Army", Sheikh Moqtada al-Sadr's militia, which is attacking the Americans? "They're here," Hassan Saleh admits. "They are organised. But we are peaceful people living in our houses, and they shoot at us."
The fault lines in Iraq's Shia community suddenly rise to the surface. "This is the man we follow," says Amer Saleh, holding up a picture of the aged Ayatollah Ali al-Sistani, Shia Islam's highest authority and a force for moderation.
And Moqtada al-Sadr? "That is an embarrassing question," Hassan Saleh says. Because it is divisive? The 30-year-old fireman, standing in the battlefield of Sadr City, nods in agreement.