Thomas Rogers' was checked "fairly regularly"
Whipps Cross University Hospital, in Leytonstone, east London has revealed a consultant in emergency medicine will lead the inquiry.
Dr Ruth Brown chairs the London Group of Consultants and has worked in the casualty department of Kings College Hospital, London, for the last six years.
Hospital bosses have pledged to make the findings of Dr Brown's "swift and thorough" review public.
Peter Coles, chief executive of Whipps Cross said: "This review will be independent, fair and balanced, with the findings being made public as soon as possible.
"By acting in this transparent way, I hope to re-assure Mr Rogers' family that we are treating the death of their father with the utmost seriousness.
"I undertake to listen to, and act upon, any findings made regarding the care and treatment of Thomas Rogers."
Mr Rogers, 74, was taken to the hospital on 14 August, needing treatment for burns, after he collapsed unconscious against a radiator at his sheltered accommodation home in Woodford Green, Essex.
His condition was assessed by a triage nurse who decided Mr Rogers was a medium priority patient when he arrived at the department.
Mr Coles said the accident and emergency ward had been very busy when Mr Rogers was admitted, but he said a doctor should still have seen the patient during his nine-hour wait.
"It is not acceptable that he was left for nine hours without seeing a doctor," Mr Coles told the BBC on Tuesday.
Mr Rogers' condition was checked "fairly regularly" by nursing staff, who decided he remained "stable".
'Died alone'
But when a nurse went to check at 0210 BST on 15 August he was found collapsed in a cubicle and pronounced dead 10 minutes later, despite the efforts of an emergency resuscitation team.
Mr Rogers, a widower who was born in Gateshead, Tyneside, moved to Essex 25 years ago to work as an engineer at the Dagenham Ford plant.
He leaves three sons, Les, Alan and David.
His family believes he might have survived if he had been seen earlier.
Alan Rogers said: "He died without anybody being there, no family whatsoever. He died alone in hospital."
Les Rogers, 49, of Fenham, Newcastle, agreed: "How could this happen? What other case was more serious than my dying father?
'Natural causes'
"We don't believe anyone has gone out there to kill him, and we are sure they are hard-working people, but it is a terrible thing that has happened.
"There's no way he should be dead. He should be here with us."
A spokesman for the Walthamstow coroner said a post mortem examination showed Mr Rogers had died of an aneurysm, which was classed as natural causes and no inquest would be held.
A Department of Health spokesman said: "We want to see the results of the investigation as soon as possible and have asked that the family see those results."