The towering highrise was, by all accounts, a good place to live: Wealthy businessmen and their families lived in the building that was conveniently located in central Urumqi, not far from the city's Grand Bazar.

One Uyghur man told DW his uncle and aunt were proud to live in the expensive, spacious apartment on the 19th floor and had spent a lot of money furnishing the large rooms. The family had moved to Urumqi, Xinjiang's capital, from Hotan province, to provide a better education for their children.

But things didn't go according to plan.

First, the uncle got caught up in Beijing's repressive crackdown on Uyghurs. He was one of several residents of the building who disappeared into a network of controversial prison camps built across Xinjiang with the purpose of "re-educating" Uyghurs.

Then, disaster struck again. On the evening of November 24, a fire broke out on the 15th floor of the apartment building and spread quickly upward. At least 10 people were killed and nine others injured from inhaling toxic fumes, according to Chinese authorities. However, activists have contested that figure, claiming dozens more were killed in the blaze.

'Time is critical'

Given Beijing's near-ubiquitous control of Chinese media, the internet and domestic communications, receiving reliable information from China is especially challenging —  particularly about Xinjiang.

DW's investigative unit spoke to several sources with close knowledge of the building, as well as apartment owners, relatives of the victims and firefighting experts. DW also reviewed extensive video footage of the blaze to establish what happened that fateful night.

What is clear is that firefighters struggled to get close to the building, as documented by several videos verified by DW.

In multiple videos, firefighters could be seen using a fire hose to put out the blaze, yet the water fell short of its target. In other videos, firefighters were seen attempting to remove bollards, special barriers to curb traffic, in a bid to get closer to the building.

"Time is critical," Sean DeCrane, director of safety operational services for the International Association of Fire Fighters, told DW.

"The synthetic products we have in our homes and apartments produce hydrogen cyanide, carbon monoxide, among a number of deadly gases, and those gases will incapacitate occupants much quicker than the fire will."

Cause of deaths

At the time of the fire, Urumqi had been under lockdown for more than 100 days. As a result, Chinese social media channels were inundated with messages of shock and grief that heavy-handed measures to contain coronavirus outbreaks may have contributed to the deaths.

But was that the case?

Many residents were unable to escape quickly enough, sources with close knowledge of the building told DW, because those in official quarantine had been restricted to their apartments.

Images circulating on Chinese social media channels showed padlocked doors in stairwells that served as fire escapes. Although DW was unable to verify these images, the sources said such tactics had been used there by authorities.

One man, who wished to remain anonymous out of fear for his relatives' security back home, told DW that whenever a member of a household was positive, their flat was locked, effectively confining every family member to the residence.

Residences that tested negative were not locked in, but devices were installed on front doors, he added, which would alert authorities when residents tried to leave their homes.

Instead of acknowledging the potential impact such containment measures may have had on evacuation efforts, authorities placed responsibility for the deaths on the victims themselves.

"Some residents' abilities to rescue themselves were too weak," said Li Wensheng, head of the Urumqi City Fire Rescue department.

Getting information out

The morning after the fire, in faraway Switzerland, Abdulhafiz Maimaitimin received a rare call from a friend: Uyghurs outside of Xinjiang know all too well that a mere phone call or message from abroad can lead to imprisonment back home.

His friend, he told DW, shared the tragic news that his aunt and her four children had all perished in the fire. The youngest child, Nehdiye, was only five years old. "I couldn't believe it," he said. "My world was turned upside down."

For days, he couldn't drink or sleep and felt dizzy. "She is dead because of China's zero-COVID policy," he said.

Maimaitimin said he had received confirmation from someone back home that apartment doors had indeed been locked. But, fearing he might endanger them, he was unwilling to share more about his source.

Two other sources told DW that the fire escape on at least one of the several blocks that make up the building was padlocked, meaning residents had to rely on two small elevators that operated in each block to escape. But soon, both sources added independently of each other, the electricity was turned off by community workers, effectively trapping fleeing residents inside.

The cost of speaking out

It is unclear how quickly authorities were able to evacuate the building and whether the entire building was vacated as firefighters struggled to contain the blaze. What is known is that it took them nearly three hours to put out the fire.

Those who have dared to question the official narrative on social media have been met with fines and arrests. The Urumqi police department announced that it had detained a 24-year-old woman for posting "false information" regarding the death toll of the fire. It called on others to "resist online rumors" and "jointly maintain order in epidemic prevention and control."

For Uyghurs living abroad, many of whom had not heard from loved ones in years, the fire offered a brief window of opportunity to contact family members in their native Xinjiang.

Yet, as abruptly as that window opened, all contact effectively ceased, sources told DW, as residents from the charred apartment block were moved to other locations in line with China's coronavirus containment measures.

Additional reporting by Esther Felden.

Edited by Lewis Sanders and Sandra Petersmann.