Ambulances taking 30 minutes to arrive at the scene of the Manchester Arena bombing was "unacceptable", the public inquiry into the terror attack has heard.
Lawyers for the 22 bereaved families said the failure to meet the standard emergency arrival target time of seven minutes was part of an "inadequate" overall response from North West Ambulance Service (NWAS).
The probe into the May 2017 atrocity has heard that only three paramedics ever entered the City Room foyer of the venue where suicide bomber Salman Abedi had struck.
In a closing submission, Guy Gozem QC told inquiry chairman Sir John Saunders: "On the evidence you heard, the need for paramedics in the City Room was clear.
"Police officers and others had charged into the City Room showing immense bravery, but they lacked the knowledge, equipment and training to adequately treat those in the City Room.
"They expected the paramedics to follow them in, they then requested them repeatedly. They were desperately hoping the paramedics would soon attend in droves and it never happened."
He went on: "NWAS ambulances didn't arrive until after 11pm.
"We heard some evidence that the evening was a busy night for NWAS and we can all appreciate the difficulties and strains that the ambulance service operates under.
"The target for the deployment of an ambulance to any single incident is seven minutes, but for this incident, involving the most serious injuries and harm, in the centre of one of Britain's largest cities, at a time when the (terror) threat level was set at severe, the ambulances didn't appear until 30 minutes after the attack.
"There has been no satisfactory explanation of this unacceptable state of affairs, we submit."
Members of NWAS's specialist Hazard Area Response Team (Hart) should also have been deployed earlier, said Mr Gozem.
Two Hart members entered the City Room 45 minutes after the blast when they were diverted from another call in Stockport, but a second Hart team was not summoned immediately, he said.
"They shouldn't have been left waiting at their home base, nor should they have been waiting at the RVP (rendezvous point) effectively - but through no fault of their own - twiddling their thumbs while those who lay injured in the Arena most desperately needed their help," he said.
"Those members of the Hart team needed to be at the Arena sooner, to be deployed into the City Room sooner and in greater numbers. Their skills, their training, their experience were lost for much of the most valuable period. That can only ever be viewed as a significant failing."
Ordinary paramedics who started arriving at the adjoining Victoria railway station from about 11pm should also have been sent into the City Room, Mr Gozem argued.
"It clearly wasn't entirely guaranteed safe even after 11pm, but there had been armed police who had gone through it. The City Room was filled with police officers who had made their own assessments as to safety based on first-hand information.
"We submit it was safe enough for ordinary paramedics."
Mr Gozem said the removal of casualties by police and members of the public from the City Room on advertising hoardings, railings and other makeshift items was "undignified, unsafe and unnecessary".
He said there was a failure at operational level by NWAS to adequately command the situation and a resulting lack of situational awareness.
"The impression from the evidence, we submit, is that they were always reacting, always playing catch-up, that events happened to them and that NWAS did not take control of the situation."
Another failure was joint working with a lack of communication between NWAS staff and other emergency services, he added.