London (CNN) -- A British coroner has cleared the emergency services of failing to respond quickly enough when a series of bombs tore through London's transport system on July 7, 2005.
Recording a verdict of unlawful killing in the deaths of 52 people on 7/7, Justice Heather Hallett ruled that the severity of their injuries meant each of them would have died, no matter how quickly help reached them.
In the wake of the suicide bombings -- on three tube trains and a bus during the morning rush-hour -- there were claims that police and firefighters had been unwilling to get close to the scenes of the blasts because of safety fears.
But Hallett praised all those on duty that day, insisting that emergency crews "did all that they could to ensure that lives were saved."
In her report into the disaster, the coroner said that the best and worst of humanity had been on display in London on 7/7.
"At each and every scene ordinary men and women, whether victims of the attack, passers by or those acting in the course of their professional duties, reacted with extraordinary courage, composure and compassion," she said.
Hallett said there were "lessons to be learned from 7/7, and improvements to be made," calling for a review of major incident training, and recommending that first aid equipment be carried on all London Underground trains.
The families of some of those who died in the blasts welcomed the coroner's verdict, which came at the conclusion of a six-month inquest.
"All the families I represent would like to thank everyone involved in these proceedings," said solicitor James Carlton.
"Whilst the sometimes traumatic proceedings will not bring back their loved ones, all involved have been united in their concern to ensure that the horror they have had to face is avoided wherever possible in the future."
British Home Secretary Theresa May said she hoped the conclusion of the inquest would "bring some measure of comfort to the families and all of those affected."
She pledged that the government would consider the coroner's report and recommendations.
The inquest heard from 300 witnesses, including those caught in the explosions, London Underground staff, police and emergency personnel.
But perhaps the most significant witness was a senior figure from the security service MI5, who was asked to account for how it was that two of the four bombers -- three British males of Pakistani descent and a Jamaican-born man -- were photographed as part of a separate terror investigation, but not followed up.
Witness G, as he was known, expressed regret that MI5 had missed the significance of Mohammed Siddique Khan and Shehzad Tanweer, but rejected any suggestion of intelligence failings.
In her report, Hallett expressed concern at the ease with which Khan, Tanweer, Jermaine Lindsay and Hasib Hussein acquired the knowledge and equipment to construct their backpack bombs.
"It is a sad fact of 21st century life that those with evil intent may search on the internet and obtain the information they need to build explosive devices," she said.
Hallett said the security services faced a massive challenge in trying to respond to every terror threat faced by the UK, and praised their work -- adding that "any suggestion [they] might have done more to prevent the attacks was inevitably based to a considerable extent on hindsight."
But the coroner had strong words for MI5's failure to make the most of the surveillance photo of Khan and Tanweer, describing it as "dreadful."
Graham Foulkes, who lost his son David in the attacks, said it was unprecedented for the security services to be criticised in this manner by a senior judge.
John Taylor, whose 24-year-old daughter Carrie died on a train approaching Aldgate tube station, said he had felt compelled to attend the inquest to find out why the disaster happened.
"The day Carrie came back to Billericay in a coffin I remember sitting in the chapel with [my wife] June and my son Simon and making a promise to Carrie to find out as much as I possibly could," Taylor told CNN.
Speaking after the verdict was announced, Taylor said the case held important lessons for the future.
"We must make sure that we never become complacent again -- that's what this inquest, what the recommendations are about.
"Bin Laden may very well be dead, [but] there are other people who will come and take his place, there are other individuals that will act on their own initiative, and we have to be careful about that. Let's make sure we get it right."
CNN's Bryony Jones, Pete Wilkinson and Andrew Carey contributed to this report.