Video report by ITV News Correspondent Martha Fairlie
Confusion and a communication breakdown at the scene of the London Bridge terror attack prevented emergency services helping victims as quickly as possible.
It resulted in police and members of the public being left to treat the victims without the help of paramedics.
The inquest was also told one of those injured might have been saved had they received quicker medical attention.
Paul Woodrow, direction of operations at the London Ambulance Service (LAS), said initially LAS struggled to get "overall situational awareness" at the "chaotic" scene of the attack.
The inquest heard that shortly after the attack, armed police officers stopped medics entering the courtyard area around the Boro Bistro restaurant, where some of the attack victims died, owing to reports of shots being fired nearby.
LAS medics were aware of patients requiring treatment in the courtyard, but were unable to reach them as a high security "hot zone" was placed over the Borough Market area.
Jonathan Hough QC, counsel to the inquests into the attack victims’ deaths, said: “Two groups of people were aware of casualties potentially requiring urgent treatment in the general area of the Boro Bistro court yard."
He added: “Neither of those groups got the message to the people in the courtyard that ambulance staff couldn’t get to them.”
Mr Woodrow said that the “chaotic” aftermath of the attack had contributed to “confusion” and “issues around communication”.
He said: “It hindered our ability, jointly, to get full situational awareness on that situation.”
Mr Woodrow said emergency service workers were receiving information covering multiple locations within a wide area, which some staff “would not have an intimate knowledge of”.
“In the very early stages of these incidents, they really are chaotic, and it’s just a fact that we do not have an army of people there to filter the information,” he said.
He admitted it “took too long to make a decision to commit” specially trained ambulance intervention teams, made up of ambulance, fire brigade and armed officers, to search for victims.
Gareth Patterson QC, representing the families of some of the victims, told the inquest that paramedics had not entered the courtyard area until after 1am, despite the attackers being killed at 10.16pm.
Mr Woodrow said the area had been deemed unsafe, that the “hot zone” had been established by police and was changing as the attack’s aftermath unfolded.
He said the LAS could not make an independent decision to deploy specialist teams, requiring input from police and fire services.
Mr Patterson said there was no evidence whether the courtyard area specifically had been designated as a “hot zone” or not.
Khuram Butt, 27, Rachid Redouane, 30, and Youssef Zaghba, 22, killed eight people and injured 48 others in a van and knife attack on June 3 2017.
They mowed down pedestrians on London Bridge before stabbing innocent bystanders at random in nearby Borough Market.
Xavier Thomas, 45, Christine Archibald, 30, Sara Zelenak, 21, Sebastien Belanger, 36, James McMullan, 32, Kirsty Boden, 28, Alexandre Pigeard, 26, and Ignacio Echeverria, 39, all died.
Mr Woodrow said that despite issues, medics working in “really difficult circumstances” had done “really good work” treating victims – and praised those who volunteered to enter the potentially dangerous “hot zone.”
“I’m proud of my staff who put themselves in harm’s way,” he said.
The inquest heard that under normal procedures, ambulance crews would never enter a high risk hot zone, but the rules were broken to send in volunteers on the night of the attack.