On the morning of 7 July 2005, four suicide bombers targeted London's transport network.
We now know that three bombs were detonated on the underground and an hour later a fourth exploded on a bus, killing 52 people and injuring hundreds of others.
But on the day itself, there was confusion for hours about the details of the scale and nature of the attacks.
On today's Sky News Daily, Gareth Barlow speaks to our crime correspondent Martin Brunt, who recalls his experience of reporting for Sky News on that day and considers its lasting impact.
Producer: Soila Apparicio
Editor: Wendy Parker