Hundreds of thousands of petals floated from the ceiling of St Paul's Cathedral in tribute to those who died in Asia's tsunami.
From jasmine and lotus to hibiscus and rose, each petal signified the loss of a life in the 12 countries affected by the disaster.
The moving spectacle came during a national memorial service attended by more than 1,800 people, including the Queen and the Prime Minister.
Four and a half months after the natural disaster, the cathedral was packed with mourning relatives, survivors and aid workers.
The bells of St Paul's rang out as the Queen arrived at the cathedral which was filled with bouquets of flowers, including roses to symbolise peace and rosemary to signify remembrance.
A Thai musician, Dusadee Swangviboonpong, played a lament on the sor-u, a Thai fiddle made from coconut shells.
Aprocession of 22 representatives from the families and affected countries walked down the aisle with candles and flowers. During a two-minute silence, the 300,000 petals were released from the galleries and dome. As a coloured haze filled the cathedral, tearful families raised their arms to catch the petals.
Among the mourners was Lord Attenborough, the film director, whose granddaughter, daughter and her mother-in-law died in Thailand.
Lord Attenborough read from the Book of Revelations: "And I saw a new Heaven and a new Earth; for the first Heaven and the first Earth had passed away, and the sea was no more."
The Archbishop of Canterbury Dr Rowan Williams told the congregation: "Somewhere, whatever our level of faith or of doubt, we need a place where we can say something about what is left when the waters have gone down, where we can affirm the fact love survives, and so renew our hope."
It was on Boxing Day that an earthquake on the Indian Ocean floor off the western coast of Sumatra in Indonesia triggered a series of devastating waves. An estimated 273,800 people were killed - and thousands are still missing. Of those who died, 124 were British and a further 21 Britons are missing.
Linda Lilley, whose son Jeremy Stephens, 29, from Norwich, was killed on Phi Phi, said: "We are pleased we have the opportunity to meet other people and to talk without crying too much." Brenda Willgrass, the mother-in-law of Louise Willgrass, 43, who died in Phuket, added: "They should never be forgotten."
John Metcalfe, 24, from Liverpool, who suffered severe leg injuries at Ko Phi Phi, plans to return to Thailand to work as a volunteer when his leg heals. "It will be a mixture of sadness for the people who died and relief I managed to escape," he said.Reuse content