TWO Hampshire firefighters were caught in a "sudden massive escalation" in a blaze that claimed their lives, an inquest heard.
They were one of two teams of firefighters who first accessed the burning flat on the evening of April 6, 2010.
Their colleagues Keith Holland and Liam Ryan were "just about able" to exit the flat despite being in "pain and physical distress", the hearing in Southampton was told.
Liam Ryan himself needed help from his colleague after becoming caught up in fallen cables as the fire escalated.
But an inquest heard that there was nothing further the men could have done to help Mr Bannon and Mr Shears.
The conditions were so bad that it took a further three quarters of an hour before the two St Mary's Red Watch firefighters were found unconscious on the floor.
Crews were "beaten back" by the heat as they tried to enter the property.
Coroner Keith Wiseman said it was highly likely the men were completely overcome by the conditions in the flat by about 9pm.
They were finally located and pulled out of the building at around 9.40pm.
Mr Bannon was pronounced dead at the scene and Mr Shears at Southampton General Hospital.
The inquest heard how the blaze started after the occupant of the flat, Karl Hoffman, hitched a curtain up over a lamp while vacuuming the flat.
He tried to extinguish the flames using soft drink and his polo shirt.
Yet the blaze soon took hold and a neighbour dialled 999.
The inquest into the deaths of the two men started this morning and is expected to last four weeks.