Poor communication and a lack of basic medical supplies hampered the 7 July bombings rescue operation, a London Assembly report has found.
Hundreds of people were injured in the 7 July attacks
While recognising their heroic efforts, the report found rescuers underground could not use radios and some relied on mobile phones, which were overwhelmed.
In the rush to save lives, details were not taken of the walking wounded, who may have needed trauma counselling.
The report calls for digital radios for emergency services as soon as possible.
Committee chairman Richard Barnes said there had been "incredible acts of courage" by emergency workers, Tube staff, NHS staff and ordinary people but this was in spite of communication problems.
Only hospitals with casualty units were put on alert. Great Ormond Street children's hospital, near the Russell Square site, was never alerted - although a field hospital was set up.
Shortage of medical supplies
Failure to deal with survivors
Police, fire and ambulance staff all used different radio systems and rescuers at ground level could not talk to their colleagues underground.
Some relied on mobile phones, but the network was put under so much pressure that it failed.
And Mr Barnes said it was "unacceptable" that recommendations for an underground communication system, made after the King's Cross fire 18 years ago still had not been implemented.
The London Ambulance Service was overwhelmed by the number of attacks - leading to a lack of stretchers and other basic equipment.
One paramedic described running to a department store to get extra bandages.
Ben Thwaites, who was wounded in the Edgware Road blast, described how passengers were trapped for 40 minutes underground and could not get to the first aid box on the train.
"People were literally holding others together, tying up with ties, etcetera.
"And then when...I was sent to get help from paramedics, they didn't have any equipment with them, they didn't have any clearance to go into the tunnels, their communications seemed to have broken down."
The report also revealed that hundreds of people walked away from the scene without any details being taken - so were unlikely to have been offered trauma counselling.
Mr Barnes told BBC London there was no evidence that the failings had cost any lives on the day.
But he concluded: "London's emergency plans have been tested, practised and refined, but on July 7 it was clear that they ignored the needs of many individuals caught up in the attacks."
In a statement, the London Resilience Partnership, which represents the key emergency services, said: "The sheer scale and unique nature of events on 7 July mean that naturally there will be lessons to learn about our response.
"Some issues have already been recognised and acted upon, such as communications systems and problems with radios underground."
And Transport for London said it was investing nearly £2bn in a modern radio network which was being rolled out, line by line, on the Tube this year and next.
The Metropolitan Police said it and the British Transport Police felt their radio systems worked well and they were able to work around the difficulties communicating underground.
"We didn't feel that was detrimental to our response," said Asst Comm Alan Brown.
Fifty-two people were killed and hundreds injured by four suicide bombers on the London Underground and a bus in Tavistock Square.
Many survivors want a full-scale public inquiry into the attacks - but the calls have so far been resisted by the government.
Prime Minister Tony Blair said lessons had already been learned, but the government would study the report in detail.