The US military suggested that Daesh was responsible for the slaughter. But an AP investigation suggests that is not the case.
After an American air strike killed more than 100 Iraqi civilians in a house in the western part of Mosul in March, US officials suggested Daesh was to blame for the horrific toll, saying militants may have crammed the building with people, booby-trapped it with explosives, then lured in an air strike by firing from the roof.
None of that happened, survivors and witnesses told The Associated Press (AP), recounting the deadliest single incident in the months-long battle for the Iraqi city.
"Armed men in the house I was in? Never," said Ali Zanoun, one of only two people in the building to survive the March 17 strike. He spent five days buried under the rubble of the building, drinking from a bottle of nose drops, with the bodies of more than 20 members of his family in the wreckage around him.
Instead, Zanoun and others described a horrifying battlefield where air strikes and artillery pounded neighbourhoods relentlessly trying to root out Daesh militants, levelling hundreds of buildings, many with civilians inside, despite the constant flight of surveillance drones overhead.
Displaced families scurried from house to house, most driven out of their homes by Daesh, who herded residents at gunpoint out of neighbourhoods about to fall to Iraqi forces and pushed them into Daesh-held areas.
Increased use of bombardment has made the fight for Mosul's western sector, which began in mid-February, dramatically more destructive than fighting for its eastern half.
More than 1,590 residential buildings have been destroyed in western Mosul, based on analysis of satellite imagery and information from local researchers, the UN said last week.
Air strikes killed 1,254 people in western Mosul in March and April alone, according to Iraq Body Count, an independent group documenting casualties in the war, cross-checking media reports with information from hospitals, officials and other sources.
In comparison, an estimated 1,600 civilians were killed or wounded from all causes during the 100-day campaign to recapture Mosul's less densely populated eastern half, which ended in mid-January.
Official figures from the Pentagon, which is slower in confirming deaths, are far lower: it said over the weekend that it has confirmed coalition air strikes killed at least 352 civilians in Iraq and Syria combined since the campaign against Daesh started in 2014.
Human rights groups have pointed to looser rules introduced by the US military in December that allow commanders on the ground to call in air strikes, eliminating a layer of vetting of the targets by officers in Baghdad intended to limit civilian deaths.
The US military says the rule change has not played a role in greater civilian casualties and that the forces adhere to the same standards for carrying out a strike.
US Central Command has refused to comment on the March 17 strike until its investigation is finished and released.
The AP spoke to seven witnesses, including neighbours and people who had been in the house, all of whom said no one was forced into the building, where dozens had taken refuge, thinking it would be safe amid the fighting raging around them. It was not on a main road and it was only two stores tall, making it unlikely Daesh militants would use it as a sniper's position that might be targeted by an air strike.
And, they said, the militants did not rig the building with explosives.
The building's owner, Tayseer Abu Tawfiq, was a businessman beloved in the neighbourhood for his generosity to the displaced. Whoever showed up, he squeezed into his house, alongside his own 14-member family – well over 100 people. A pregnant woman taking refuge there gave birth on March 15. The next evening, Abu Tawfiq's neighbour spoke to him and told him it wasn't safe having so many inside.
"I can't turn people away," Abu Tawfiq replied, according to the neighbour, Abdullah Khalil Ibrahim.
Hours later, the house became a death trap.
A brutal battlefield
Western Mosul is a far tougher battleground than the city's eastern sector on the other side of the Tigris River.
Its neighbourhoods are older, more densely populated and more tightly packed with houses.
Its history also plays a role: former dictator Saddam Hussein distributed property to members of his military and intelligence agencies in the area, and after his fall in 2003 many of them joined the Sunni insurgency, Al Qaeda and later Daesh. The neighbourhood where the Abu Tawfiq home was located was home to many of these Saddamists-turned-Daesh fighters.
The militants routinely use civilians as human shields and fire from residential buildings, according to US and Iraqi officials, residents and human rights groups. They punch holes in the walls of buildings to create passages for fighters to move without being seen. They plant cars packed with explosives, which coalition forces have to bomb so troops can advance. Days before the March 17 strike, a missile hit a Daesh car bomb a few blocks away, destroying a nearby building and killing 27 people taking refuge inside.
But there are other differences. The fight for eastern Mosul was led mainly by US-trained elite counter-terrorism units. In the west, they have been joined by federal police units with little experience in urban combat and the battle has relied more heavily on artillery and air strikes.
The top commander of the US-led coalition, Lt. Gen. Stephen Townsend, called western Mosul "the toughest and most brutal close-quarters combat I have experienced in my 34 years of service."
In the case of the March 17 strike, an Iraqi security official said it was called in when Daesh fighters were seen moving house to house along rooftops, firing at Iraqi forces. Militants were also seen in the streets nearby, said the official, who spoke on condition of anonymity to discuss operational details.
The military did not know civilians were crowded inside, he said.
Mosul's governor, Nofal al Akoub, refused to comment, pending the outcome of the investigation.
"In battle, military mistakes are made. But all mistakes are ultimately because of the presence of Daesh" among the population, he said.