The capital was still reeling from the murder of 52 people on July 7 when terror returned to the streets a fortnight later.
The failed bomb attempts of 21 July caused chaos, fear and misery - people simply couldn't believe it was happening all over again.
At the time, BBC News received hundreds of e-mails and pictures from a confused and concerned public.
Some were frighteningly close to the attempted explosions on three Tube trains and a bus, while others watched from behind the police cordons, fearing the worst.
An unlucky few were caught up in both the 7 July and 21 July attacks.
Eunice Olwa is still haunted by the image of a man lying spread-eagled on the floor of her Tube train, with a smoking rucksack on his back.
"His eyes were tightly shut, then he opened them and looked up at us before closing them again," she said.
"He thought he had killed us and it was a shock to him that he was still alive."
Ms Olwa was taking the Tube from Latimer Road to Shepherd's Bush when the man sitting opposite fell to the ground.
"I saw someone with a phone and he was agitated but I thought he was just in a hurry," she said.
"Then the explosion happened and he fell down. A lady shouted: 'It's a bomb' and everyone scattered to the next carriage. Some were screaming, some were crying. Everyone was confused."
When the Tube came to a stop, the suspect jumped the train and "casually" walked off down the tracks, she said.
During the trial, one of the defendants claimed the plot was just a hoax to "frighten people", but Ms Olwa is certain of their intention.
She said: "I was there and I saw what I saw. His intention was to kill himself and all of us. It's just plain murder."
Arthur Burton-Garbett was on a train heading to Oval station when a bomb failed to detonate in the next carriage.
The 72-year-old can recall the day like it was yesterday.
"I was standing up near the inter-connecting door when I heard an explosion. It sounded like a pistol shot," he said.
"A second or so later fumes came into our carriage and it reminded me of cordite."
During his national service, he had worked at a Ministry of Defence establishment which tested ammunition and so he knew instantly what had happened.
He said: "I had realised a detonator had gone off but hadn't activated anything. I thought to myself: 'It's only been a fortnight but it's happening all over again.'"
The antiquarian bookseller can remember that a man and three women "filtered silently" into his carriage and one of them pulled the emergency cord.
"They looked a bit shocked," he said. "I don't think they realised what had happened."
When the Tube came to a stop at Oval, he watched the suspect leap from the train and he immediately gave pursuit.
"He went up the escalator like a hare but I had to stop half-way up," he said.
"There's no question of heroics. Someone had attempted to murder me and everyone else around, so I didn't see why he should get away with it."
Contents of a failed bomb were left on a Tube train
Mr Burton-Garbett said it took a few days for the enormity of the situation to sink in. And it wasn't until March this year, during the trial, that he realised just how lucky he was to be alive.
He said: "A team of scientists had replicated what the effect would have been. The bomb would have wiped out everyone in the bomber's carriage and my carriage. We would have been obliterated.
"There's no doubt about what these bombers intended to do and as far as I'm concerned they should get life."
For those not on the three trains or No26 bus, the first indication that something was wrong came with the flashing lights and whirr of sirens.
Buses were evacuated, Tube stations were closed, roads were shut, people couldn't get to work - confusion reigned.
But many of the e-mails spoke of defiance and how the British public would not be cowed.
As Mr Burton-Garbett put it: "They haven't stopped me getting on with my life. If you go about life thinking death is around the corner, you will not get anywhere."