Londoners are today remembering those killed and injured in the July 7 bombings on the fifth anniversary of the terrorist attacks.
The atrocities carried out by Islamic extremists on Tube trains and a bus in 2005 left 52 innocent people dead and more than 700 injured.
No official events are planned to commemorate the anniversary, although wreaths will be laid on behalf of Prime Minister David Cameron and London Mayor Boris Johnson at the Hyde Park memorial to the victims.
Many survivors and bereaved families will mark the day with private gatherings at the memorial and the sites of the four blasts.
The lack of an official ceremony has upset many of those affected by the tragedy, according to Graham Foulkes, whose 22-year-old son David was killed in the Edgware Road bombing.
Mr Foulkes said: "I am very disappointed. This was an attack against the country. This is the fifth anniversary, a significant one, but even the Mayor of London will not be present.
"I don't think any of us are saying we want this to become an annual major event, but I think on the fifth anniversary the least the Prime Minister could do is attend and lay a wreath.
"This was a national attack, and it's really disappointing. I know it's upset many people."
He contrasted Britain's attitude to marking the 7/7 anniversary with the active approach taken to remembering the 9/11 attacks in the United States.
"The mindset of New Yorkers and the authorities in New York is completely different to here," he said.
"The Americans had an independent inquiry. Here we can't even get the inquests to run within a reasonable timetable.
"Here we are at a significant anniversary and even the Mayor can't be bothered to attend."
In previous years Mr Foulkes and his wife have marked the anniversary by visiting their son's grave, but this year they will travel to London and meet other families at Edgware Road.
Transport for London is organising private rooms and trained support staff for bereaved relatives and survivors near the sites of the three Tube bombings.
The Department for Culture, Media and Sport (DCMS), which is responsible for organising 7/7 memorials, said none of the families had contacted it since last year asking for an official event to mark today's anniversary.
A spokesman said: "At the request of the families of the victims, there is no formal ceremony this year, their view being that the opening of the permanent memorial by the Prince of Wales last year was the appropriate way to finish that stage of their grieving."
A spokeswoman for Mr Johnson said the Mayor followed the advice of the DCMS on marking the anniversary.
July 7 2005 dawned with London still elated from learning the previous day that it had won the 2012 Olympics, but the euphoria was short-lived.
Suicide bombers Mohammed Sidique Khan, 30, Shehzad Tanweer, 22, Hasib Hussain, 18, and Jermaine Lindsay, 19, met at Luton station that morning.
They took a train to King's Cross in London, then hugged and separated to carry out their deadly missions.
Within three minutes of 8.50am, Tanweer detonated his bomb at Aldgate, Khan set his device off at Edgware Road and Lindsay blew himself up between King's Cross and Russell Square.
Hussain detonated his device on board the number 30 bus at Tavistock Square at 9.47am.
A fortnight later, another four would-be suicide bombers launched failed attacks on the Tube and a bus, leading to police marksmen shooting dead innocent Brazilian Jean Charles de Menezes.
The inquests into the deaths of those killed in the 7/7 atrocities will finally be held at the Royal Courts of Justice in London this autumn.
Ken Livingstone, who was London mayor at the time, said: "July 7 2005 was a day we will never forget.
"It was a day in which many people were caught up in an act of horrific criminal violence and a day when Londoners also demonstrated why this city is the greatest in the world.
"Londoners from all communities united against the appalling acts of terror and chose hope and humanity over division.
"I hope that people across London today will spare some time to reflect on what happened five years ago, the people whose lives were lost and those who were caught up in the events, and the great bravery and solidarity of Londoners we saw on and after the 7th."
The secretary general of the Muslim Council of Britain, Farooq Murad, will lead a delegation from the UK's Islamic community to pay their respects to the victims of the attacks at the Hyde Park memorial today.