The firefighter, described as a "reasonably strong boy", headed into the unit down a right-of-way ahead of his partner who was feeding the hose in.
Witnesses described windows exploding and flames shooting out through the roof as smoke and fire engulfed the home.
"They were coming in from the opposite end of the house from where the bulk of the fire was to cut it off and next thing the ceiling collapsed. It was pretty dramatic."
Mr Breeze said the ceiling was made of plaster, making it heavier than usual.
"Just about the whole section came down on top of him and it flattened him down and broke around some furniture."
The firefighter was in full uniform with breathing equipment on.
Mr Breeze said he tried to push free of the weight but could not.
"He could see the ranch slider through a tunnel at the end of it and he made his way across to that."
The firefighter punched out the ranch slider window just as his partner appeared and helped him outside.
As the blaze was brought under control firefighters discovered a body in one of the two bedrooms.
Police have not identified the dead person. Neighbours said a man lived at the address.
Hamilton Police CIB Detective Senior Sergeant Ross McKay said their thoughts were with the deceased's family and with the injured firefighter whom they wished a speedy recovery.
Mr McKay said police were working to identify the person who died.
The injured firefighter is expected to be back at work in two days.
