Survivors and families of the victims of Britain's worst residential fire since World War II have gathered to mark the fifth anniversary of the tragedy.
A total of 72 people were killed when a fire that started in a faulty freezer ripped through the 24-storey Grenfell Tower block in west London on 14 June 2017.
An official report blamed highly combustible cladding fixed to the exterior of the high-rise as the "principal reason" the fire spread.
But despite a costly ongoing public inquiry, the government has been accused of failing to implement urgent safety changes to prevent a similar tragedy in other high-rise blocks.
The names of each of the 72 victims of the Grenfell Tower fire have been read aloud at a memorial service at Westminster Abbey.
As each group of names was read out, the congregation replied: "Forever in our hearts."
The congregation then observed a moment of silence.
The silence was broken by the sound of an oud played by Rihab Azar.
Opening the service, the very Reverend Dr David Hoyle, Dean of Westminster, said the loss and anguish "are still vivid and sharp" as the congregation gathered "in sorrow and in pain".
He said: "Here we renew our commitment to remember those we have lost.
"We gather as those who look for justice and a renewed commitment to securing safety in our homes, safety in times of fire.
"Grateful for the support of the communities and individuals that have sustained the bereaved and the survivors over the last five years, we meet in faith and hope looking to a better, safer, surer future."
Members of the Grenfell Next of Kin group, which represents those bereaved by the tragedy, said they do not want their loved ones' deaths to have been in vain.
memorial service at Westminster Abbey
One bereaved relative said the "catastrophe is never ending for us", adding: "They lost their lives so others could live in safety.
"We don't want them to just say 'Never forget' - we want it cemented in some way."
At 2pm a 72-second silence will be observed at Westfield shopping centre, after which the names of the 72 victims will be read out over the public address system.
Later in the afternoon, cording around the tower in north Kensington will be removed so survivors, the bereaved and community groups can gather at its base for a multi-faith service and lay flowers and wreaths.
Natasha Elcock, chairwoman of campaign group Grenfell United, said: "This week will be a difficult week for everyone affected by the Grenfell Tower fire.
"For many of us the events five years ago are still so raw in our minds and our losses remain heavy in our hearts."
In the evening, firefighters from across the country will form a guard of honour as members of the community take part in a silent walk starting from the base of the tower.
Pete Wolfenden, a firefighter who responded to the blaze, said: "It's been five years since the Grenfell Tower fire and the thoughts and wishes go out from all London firefighters and fire control staff personnel to the survivors and friends and family of those who lost their lives in this appalling incident, the worst domestic blaze in living memory.
"We also remember the brave and courageous members of all the emergency services who attended on the night and subsequent days, some of who still suffer ill-health and bear the mental scars of attending that traumatic incident."
A spokeswoman for campaign group Justice 4 Grenfell said: "Today we stand with the Grenfell bereaved, survivors and community. Forever in our hearts.
"The Grenfell Tower fire has become a symbol of the social inequality and injustice that exists in our country.
"Seventy-two people lost their lives, many people lost their homes, possessions, families and loved ones.
"The first duty of any government is to protect the lives of its citizens. From the right to life and including the duty to provide adequate housing, these duties are enshrined in law and are where the government has and continues to fail."
The Times newspaper reported that some 640,000 people were still living in buildings with the same type of cladding material.
There has also been criticism of the government for advising as late as last month that residents should wait for help before evacuating during a high-rise fire.
"A lot of people who managed to survive were people who managed to get out early because they ignored the 'stay put' advice," said Tiago Alves, 25, who escaped with his mother, father and younger sister.
"I'm gobsmacked at the fact that we're still having this conversation five years on."
London Mayor Sadiq Khan praised survivors for their campaign to improve public safety.
The ongoing public inquiry was "painstakingly unearthing the truth" - that profits were prioritised over public safety and deregulation weakened building standards, he said.
"The response from the government, building developers and owners has fallen far short of what the families of the victims and survivors have every right to expect," he wrote in The Observer.
"We still have too many residents in London and across the country living in high-rise buildings that are covered in dangerous flammable cladding, and we are still seeing designs for buildings that have critical safety failings."
Additional reporting PA
