Between 9,000 and 11,000 people were killed in the nine-month battle to recapture the Iraqi city of Mosul from the Islamic State of Iraq and the Levant group (ISIL), an Associated Press (AP) investigation has found.
The civilian casualty rate is nearly 10 times higher than that previously reported.
The deaths are acknowledged neither by the coalition, the Iraqi government nor the ISIL's self-styled caliphate.
Iraqi or coalition forces are responsible for at least 3,200 civilian deaths from air raids, artillery fire or mortar rounds between October 2016 and the fall of ISIL in July 2017, according to the AP investigation.
The news agency cross-referenced morgue lists and multiple databases from non-governmental organisations.
Most of those victims are simply described as "crushed" in health ministry reports.
The coalition, which did not send anyone into Mosul to investigate, acknowledges responsibility for only 326 of the deaths.
"It was the biggest assault on a city in a couple of generations, all told. And thousands died," said Chris Woods, head of Airwars, an independent organisation that documents air and artillery attacks in Iraq and Syria and shared its database with AP.
"Understanding how those civilians died, and obviously ISIS played a big part in that as well, could help save a lot of lives the next time something like this has to happen. And the disinterest in any sort of investigation is very disheartening," Woods said.
In addition to the Airwars database, AP analysed information from Amnesty International, Iraq Body Count and a United Nations report.
AP also obtained a list of 9,606 names of people killed during the operation from Mosul's morgue.
Hundreds of dead civilians are believed to still be buried in the rubble.
Of the nearly 10,000 deaths that AP found, around a third of the casualties died in bombardments by the US-led coalition or Iraqi forces.
Another third were killed in ISIL fighters' final frenzy of violence. It could not be determined which side was responsible for the deaths of the remainder.
But the morgue total would be many times higher than official tolls.
Iraqi Prime Minister Haider al-Abadi told the AP that 1,260 civilians were killed in the fighting.
The US-led coalition has not offered an overall figure. It relies on drone footage, video from cameras mounted on weapons systems and pilot observations for investigations.
"The coalition never came to us or sent anyone else to us asking for data. They never came directly or indirectly," said Hatem Ahmed Sarheed, one of the Iraqi men responsible for recording Mosul's dead.
An AP reporter visited the morgue six times in six weeks and spoke to morgue staffers dozens of times over the phone.
|Victory over ISIL in Iraq was declared in December [Ahmad Al-Rubaye/AFP/Getty Images]|
The Americans say they do not have the resources to send a team into Mosul. Because of what the coalition considers insufficient information, the majority of civilian casualty allegations are deemed "not credible" before an investigation ever begins.
The coalition has defended its operational choices, saying it was ISIL that put civilians in danger as it clung to power.
"It is simply irresponsible to focus criticism on inadvertent casualties caused by the Coalition's war to defeat ISIS," Colonel Thomas Veale, a coalition spokesman, told the AP in response to questions about civilian deaths.
"Without the Coalition's air and ground campaign against ISIS, there would have inevitably been additional years, if not decades of suffering and needless death and mutilation in Syria and Iraq at the hands of terrorists who lack any ethical or moral standards," he added.
What is clear from the tallies is that as coalition and Iraqi government forces increased their pace, civilians were dying in ever higher numbers at the hands of their liberators.
Mosul was home to more than a million civilians before the fight to retake it from ISIL.
Fearing a massive humanitarian crisis, the Iraqi government dropped leaflets or had soldiers tell families to stay put as the final battle loomed in late 2016.
As the battle crossed the Tigris River to the west last winter, ISIL fighters took thousands of civilians with them in their retreat.
They packed hundreds of families into schools and government buildings.
They expected the tactic would dissuade air raids and artillery. They were wrong.
When Iraqi forces became bogged down in late December, the Pentagon adjusted the rules regarding the use of airpower, allowing air attacks to be called in by more ground commanders with less chain-of-command oversight.
As the fight punched into western Mosul, the morgue logs filled with civilians increasingly killed by being "blown to pieces."
Reports of civilian deaths began to dominate military planning meetings in Baghdad in February and early March, according to a senior Western diplomat who was present but not authorised to speak on the record.
After allegations surfaced that a single coalition attack killed hundreds of civilians in Mosul's al-Jadidah neighbourhood on March 17, the entire fight was put on hold for three weeks.
"Killing daesh 24/7"
Under intense international pressure, the coalition sent a team into the city for the first time, ultimately concluding that the 500-pound bomb that killed 105 people was justified to kill a pair of ISIL snipers.
Iraq's special forces units were instructed not to call in attacks on buildings. Instead, the forces were told to call in coalition air raids on gardens and roads adjacent to ISIL targets.
A WhatsApp group shared by coalition advisers and Iraqi forces coordinating air raids previously named "killing daesh 24/7" was wryly renamed "scaring daesh 24/7."
Daesh is the Arabic acronym for the ISIL group.
"It was clear that the whole strategy in western Mosul had to be reconfigured," said the Western diplomat.
But on the ground, Iraqi special forces officers said after the operational pause, they returned to the fight just as before.
The WhatsApp group's name was changed back to "killing daesh."