On a warm summer's morning, exactly a year ago today, the unthinkable happened in London.
Bill at King's Cross: the focus of one of the memorials
At 8.50am, a series of explosions ripped through three tube lines, deep under the capital's streets.
Given the chaotic nature of the London rush-hour, no-one was quite clear what had happened.
But, almost exactly an hour later, a fourth explosion tore apart a double decker bus in a quiet backstreet.
And it became clear that there had been a large-scale, deliberately co-ordinated terrorist attack on the capital.
This morning on Breakfast:
We marked the first anniversary of the London bombings, with an extended live programme.
Memorials: how to take part
Two minute silence at mid-day
Lay flowers: at Regent's Park, London (8am - 4pm)
Service and commemoration: 6pm Regents Park
Book of tributes: from Saturday
On air until 10am Friday morning, we heard the stories of some of those caught up in the events of the day.
We also looked at the lessons learned - and found out what the future holds.
Breakfast's Bill Turnbull was at Kings Cross tube station - and Kate Silverton was at Tavistock Square.
She met George Psaradakis, the man who was driving the Number 30 bus when it was attacked.
On this page, we've rounded up the ways in which you can pay your own tribute to the victims of the bombings
July 7: Breakfast's special coverage
We've put together highlights of some of the best interviews and reports - you can watch again from this page
The Culture Secretary Tessa Jowell came into the Breakfast studio.
In the days after the bombings, she was asked to be the liaison between government and the bereaved families.
Her department has organised many of today's commemorations and she is one of the few VIPs invited to join the families today - watch again from the link to the right.
And we also heard from the Commissioner of the Metropolitan Police, Sir Ian Blair, who talked about the moments when his worst fears were confirmed.
However, he said his officers had planned for a major attack - he described the horror he felt when visiting the disaster sites, but said how proud he was of his officers.
Sian met Danny Biddle as he's reunited with nursing staff
In a filmed report, Sian went to meet Danny Biddle who was young and fit, had a good job and was about to get married. Everything changed when he was caught up in the blasts at Edgware Road.
He was the most seriously injured survivor that day and was the last victim still spending much of his time receiving treatment in hospital, leaving for the last time only a few days ago. I met Danny as he returned to meet the medical team that saved his life.
Paul Dadge: "We ran into the path of the photographer"
At our King's Cross outside broadcast location, Bill met Paul Dadge
The image of Paul helping a survivor, her face covered in a bandage with holes cut in it, became iconic in the days after the bombing.
Paul told Bill how he got involved in helping the injured and how he was photographed with
injured passenger Davinia Turrell as he led her to safety.
Memorials: how you can take part
To mark the London bombings, there will be a two-minute silence across the entire country, at midday today.
Many of the memorial events are being kept deliberately low-key, at the wish of victims and their relatives.
But these are some of the key ones which are open to the public
Laying flowers: from 8am to 4pm at Queen Mary's Gardens, Regents Park. Purple carnations will be provided to lay on the mosaic in the shape of a flower with seven petals.
Regents Park: 6pm: official commemorative event, beginning with 30-minute service. The names of all those who died will be read out, and there will be readings by relatives of four of the victims and music from The London Gospel Choir. Room for 4,000 people, plus large screens for those standing further away in the park.
Memorial Plaques are being unveiled at the site of each bombing on Friday morning. They will be open for viewing by the public from 3pm.
The Book of Tributes: containing pictures, thoughts and poems by relatives of those who died can be seen from Saturday morning at The Museum of London.
There will also be special services at St George's Church, near Tavistock Square, St Paul's Cathedral and St Pancras Church, Euston.
If you need help in the aftermath of the bombings, there is a special website and helpline, which is currently open 24 hours a day. Contact the 7 July Assistance Centre on 0845 054 7444