It is a year since Melanie Smith walked into the housing offices of Barnet council and set herself on fire.

Yet her mother, Marie Bennett, fears vital lessons that could protect others have not been learned. “This didn’t need to happen – that’s the thing that hurts,” Bennett said. “I don’t think anyone has taken on board that they could maybe prevent other deaths.”

Bennett is also still waiting for answers to her questions, including about Smith’s final conversation with council housing officers, after having experienced months of anxiety about being evicted from her home of two decades. “No one has told me who spoke to her that day, or what was said,” she explained.

The nature of the tragedy that played out last August in north London seemed almost unprecedented in modern Britain.

The desperation that drives someone to self-immolation is more familiar from foreign news reports: the protests of Tibetan monks in China, of demonstrators against Soviet tanks during the Prague spring, or the Tunisian fruit seller whose suicide sparked the Arab spring.

Several people have threatened to set themselves on fire in British welfare offices in the past decade: one man is reported to have badly burned his legs. But the tragedy in Barnet House, the concrete high-rise where the council housing offices were based until recently, appears to be the only death on record.

An Observer investigation has uncovered the pressures that were building in the months before Smith’s devastating decision, and how safety nets that could have protected her in a double crisis of housing and mental health failed at the most critical moment.

It's the level of desperation that I find frightening. It's an individual tragedy but it's also an indication of harm in our society Barry Rawlings, councillor

There is no way to untangle the web of factors that contributed to Smith’s despair. But austerity policies have been linked to tens of thousands of extra deaths and a rise in suicides, studies have found, although most are private tragedies, not public protests.

“It’s the level of desperation that I find frightening,” said Barry Rawlings, a Labour councillor in Barnet, of Smith’s death. “It’s an individual tragedy but it’s also an indication of harm in our society. It suggests there needs to be a national review of policies on housing and welfare.”

Smith arrived on that afternoon in August 2018 to speak to the council’s “statutory homelessness” team, using an internal telephone system that separated staff from petitioners.

At some point during or after that conversation, she shouted: “Don’t make me do it.” An eyewitness said: “I thought maybe she was going to attack someone.”

But the desperation was turned only against herself. A security guard rapidly extinguished the flames and Smith, who was in her fifties, was airlifted to hospital, but she died after several months in intensive care.

Despite the extremity of the protest, once she was carried away in the air ambulance, she all but vanished from the public eye.

The council ordered its employees in Barnet House not to talk about the incident to journalists, sources claimed. Police confirmed only that there had been an incident and the local paper noted simply that a woman had been taken to hospital with burn injuries.

Smith’s housing crisis began when an eviction notice arrived through the post in April 2018, warning that her landlord had started legal proceedings to remove her from her home.

She had rent arrears of more than £700, which her mother said were a result of the bedroom tax. In theory, she could have moved to a smaller home, but across London there are severe shortages of social housing.

Councils have moved tens of thousands of families out of their areas and many out of the city entirely, government figures show. Residents in Barnet said they had been left with no option but to move as far away as Leicester. Smith was not offered an alternative home by the council, her mother said, and knew her chance of finding one in Barnet was extremely low. But her life was rooted in the area. An artistic woman who loved painting and writing poetry, she kept in touch with a global network of friends and family on Facebook, followed national and international politics and regularly visited a sick relative who lived near by.

“She liked art galleries, and going on marches,” Bennett said. “Some of her poems were very long, some were political, some about love and life in general.”

Smith had also wrestled with mental health problems, including at least one suicide episode. Her problems were severe enough that she qualified for a free transport pass.

Two weeks before her death, she saw a doctor and reported suicidal thoughts, her mother said. She had also visited the surgery before the tragedy at Barnet House, to ask about a form that could have exempted her from council tax on the grounds of mental impairment, helping to balance the bills.

She said things were getting on top of her and she was finding it difficult to cope. But this was beyond anything you would expect Marie Bennett, mother

The doctor certified Smith as healthy, however, and when she tried to speak to someone from the practice, she was turned away by the receptionist, she told her mother.

The local clinical commissioning group said it was unable to comment on individual cases. Depression was given as a partial cause of her death, along with burn injuries.

“I feel she was let down in such a cruel way really,” Bennett said. “She said things were getting on top of her and she was finding it difficult to cope. But it was beyond anything you would expect to happen in life. Sometimes I still think I’m going to wake up [and find it was a dream], then it hits me again, the full facts.”

Smith had several meetings with Barnet council as the eviction notices built up, but staff were apparently unable to provide her with reassurance that she would be able to stay in her home. A council spokesperson said it carried out a safety review after the incident, and remained “committed to working together with our partners in helping to support vulnerable people”, but declined to comment on an individual case.

Judges handing down eviction orders ask for proof that landlords have made genuine efforts to find a negotiated solution. So a housing association would normally send several letters and make home visits to a renter who faces losing their home.

Smith’s landlord, the Home Group, said it was unable to speak to her because she “chose not to continue to communicate with us” after falling into arrears, but had informed the council about her situation.

“Given her refusal to engage, we were unable to have the conversations we really wanted to have, which were to help her find a solution in line with what she could afford, given her level of housing benefit,” said Matt Forrest, Home Group’s director of operations. “Our thoughts were at the time, and remain with, our customer and her family and friends.”

It is unclear what Smith was told in the council offices, but her mother believes she felt that eviction proceedings were already under way and could not be stopped.

“I believe she thought they were going to repossess her home,” Bennett said. “That’s the reason it was too much.”

• Names of mother and daughter have been changed to protect family privacy.

In the UK, Samaritans can be contacted by phoning 116 123 or by email to jo@samaritans.org. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at www.befrienders.org.