“Hang in there.”

Those were the last words Mr Chung said to his wife after a huge fire broke out in their high rise public housing complex in Hong Kong ‘s Tai Po district.

It was around 15:00 local time (06:00 GMT) on Wednesday when he got her panicked phone call. She said she couldn’t get out of their flat with their cat.

He rushed home from work to find the 31-storey building in flames, with black smoke billowing out of it. Firefighters in the Chinese territory took nearly 24 hours to tame the blaze that tore through seven tower blocks, including theirs, claiming at least 75 lives so far.

Nearly 300 people are still unaccounted for – Mr Chung’s wife is among the many missing.

The BBC spoke to several residents who were not at home or managed to escape in time. Some, like Mr Chung, have waited outside the burning buildings, hoping against hope. There was no alarm warning them of danger, all of them told the BBC.

Mr Chung, 45, and his brother, spent Wednesday night on the street asking the firefighters dozens of times for updates – but they couldn’t give them any.

Throughout, he said, he and his wife kept calling each other, anxious and scared. She told him she was about to faint as the smoke got thicker and thicker.

“She probably did faint,” Mr Chung told BBC Chinese on Thursday, his eyes red from tears. “I dare not call her again.”

Given that hours had passed since they spoke, he was braced for the worst. “She passed away with our cat, who she loves,” he said, breaking down in tears. His wife was the only one in the family who didn’t go to work or school on Wednesday.

The Chungs moved in a decade ago to Wang Cheong House – the first of the seven tower blocks at Tai Po to go up in flames. When the fire started, Mr Chung says, the smoke on the 23rd floor, where they lived, turned so thick within just 10 minutes, that his wife couldn’t find her way out.

The cause of the fire is still unclear, but authorities believe renovations using flammable material and scaffolding helped spread what has now become the deadliest blaze in Hong Kong in six decades.

It engulfed seven of the eight buildings – comprising 1,800 units – in Wang Fuk Court, a subsidised housing estate built in 1983 to the north of Hong Kong Island, where the city’s wealthy live. Nearly 40% of Wang Fuk Court’s residents are aged 65 or above, according to the 2021 census.

It’s partly why it’s feared so many residents were trapped – because they are older and less likely to have made it out quickly.

Ms Fung, 40, has not been able to find her mother yet. She and her parents moved to the estate only last year – for its views of the ocean. Her father and she were at work when the fire started.

Ms Fung received a call from her neighbour, who said she was hiding with Ms Fung’s mother inside a toilet. But they lost contact at midnight on Wednesday.

All the same, she is holding on to hope: “We will think about our next steps after my mum comes out.”

She sought help from police, but she says she was furious when they called her back to ask if it was possible her mother could have somehow escaped.

She demanded to know how that was possible: “You know much better than us how badly burnt Wang Cheong House is!”

On social media, posts about missing elderly relatives, children and pets have been circulating endlessly.

A desperate mother wrote: “I still can’t find my baby girl. It’s nearly 30 hours and there has been no updates from the fire service…”

In a later post, she said: “I am afraid there is no hope.” By Thursday night she confirmed to the South China Morning Post that her child was dead.

The devastation has spotlighted the expensive and controversial renovations at Wang Fuk Court, which cost about HK$330M ($42.2M; £32.1M), with each household having to pay between HK$160,000 and HK$180,000.

Many residents had opposed the project because of the costs but it went ahead. Authorities have now arrested three executives from the construction firm, citing “gross negligence”. Police say the mesh and plastic sheets used on the scaffolding were substandard, and that windows were wrapped in highly flammable styrofoam.

Grandma Chan, a long-time resident, says she had been scared since the renovation began last year, because of its scale and she had occasionally noticed a burning smell. “Will anything happen if I stay home?” she once asked her daughter.

The 72-year-old was alone at home when the fire started but she only found out about it when her daughter, who was travelling in South Korea, called. She says she made it out alive because her daughter told her to flee.

It was the same for 82-year-old Grandma Wu. When the fire broke out, she was playing mahjong, a popular game, with her neighbours. They were warned not by an alarm, but by their husbands calling them.

But she said they continued the game because there were three buildings between theirs and Wang Cheong House, where the fire broke out. Then came a second call, saying the fire had reached their building. The women immediately took the lift and reached the ground floor.

Surrounded by the smell of burning buildings, Grandma Wu looked up to find that seven of eight buildings within the complex were in flames.

Although she was safe, she stayed outside, with her helper, overnight. She says her son wanted to take her to his home but she refused.

“I have been living in this flat for 42 years,” she says. “I told my son not to come, and I would not go anywhere. I have to sit here and watch how this goes. My heart will only be at peace after the fire is extinguished.”

When that happens, a new battle begins for many residents who have poured a life’s worth of savings into buying these homes.

Kyle Ho, 32, moved into the complex with his retired parents three years ago. Despite the subsidised price, they needed a mortgage to afford a home at Wang Fuk Court. Now, they don’t know what comes next.

The Hong Kong government has announced cash relief of HK$10,000 for displaced families, and a HK$300m assistance fund. That could be some relief for Mr Ho.

“The worst-case scenario is that we have lost our flat,” he says. “But the most important thing is that all of us are safe. We are luckier than many other families.”

For those like Mr Chung, the wait continues as authorities insist they have not ruled out rescuing people. “We haven’t given up,” they said earlier on Thursday.

Mr Chung, too, is determined to find his wife. “I want to rescue her – whether she’s alive or gone.”