In the shadow of London's Grenfell Tower, lit up in green as a silent tribute to mark the moment the fire broke out on the fourth floor of the residential high-rise a year ago, survivors and bereaved families marched Thursday carrying photos of loved ones and holding 72 white roses - one for every live lost.

It was the greatest loss of life in a fire on British soil since World War II, a horror that left the neighbourhood and the country in shock.

"Grenfell tower fire turned our lives upside down," Samia Badini from the Residents Advisory Board said.

"We had to live with trauma and try to keep strong," she said.

On Thursday, survivors, bereaved families and people around Britain are marking the anniversary of a local tragedy that's also a national shame - one for which blame still is being assigned and traded.

Was Grenfell a tragic accident, the product of government cost-cutting and lax safety standards, or authorities' disregard for people who lived in public housing?

Omar Gommari lost friends in Grenfell Tower fire.

Wearing a t-shirts, with Justice4Grenfell printed on it, that he designed to raise money for the charites helping in the initial aftermath, he told British broadcaster Sky News the anniversary will be a difficult time.

"It will bring back memories: we saw people of screaming and shouting in every kind of language and we saw people trying to throw their kids out."  

A year on, the west London neighbourhood around Grenfell echoes with sounds of construction.

The ruined tower, which stood for months like a black tombstone on the skyline, is covered in white sheeting.

Through the night, Grenfell Tower and 12 surrounding blocks have been illuminated in green, with prayers said for those who lost their lives.  

A green heart and the words "Grenfell forever in our hearts" are emblazoned at the top.

The UK prime ministerial office at Downing Street in central London was also illuminated in green, the colour of remembrance adopted after the lethal fire.

For the somber anniversary rituals, survivors will gather near the base of the tower's shell before a nationwide minute of silence at noon.

There will be vigils and marches across Britain.

The fire broke out shortly before 1 a.m. on June 14, 2017 in the kitchen of Behailu Kebede's fourth-floor apartment. Kebede woke the neighbors on his floor and called firefighters, who soon arrived.

High-rise apartment towers are supposed to be designed to stop apartment fires spreading. But within minutes, the flames had escaped Kebede's apartment and raced up the outside of the 25-story tower like a lit fuse.

Many residents fled, but some on the upper floors observed official fire-safety advice and stayed put. The fire brigade changed the guidance at 2:47 a.m. By that time, the building's only stairwell was smoke-filled and treacherous.

Several people died trying to get out. Others perished in their homes as they waited to be rescued, or died in neighbors' apartments where they'd taken shelter. Three people were found dead outside, having fallen or jumped from the tower.