The Commerce Department's National Institute of Standards and Technology also found the large open display space and large quantities of flammable furniture increased the spread of the flames at the Sofa Super Store in July 2007.
The long-awaited draft report also suggested that firefighters breaking front windows about 40 minutes after the blaze was reported let the flames spread quickly through the showroom.
However Nelson Bryner, who led the study, said by the time that was done -- four minutes after a firefighter inside radioed a Mayday -- conditions inside the building were already untenable for the firefighters.
The institute conducted complex computer modeling to determine why the fire spread so quickly, why the building collapsed and whether sprinklers could have saved firefighters.
The modeling did find the fire, which broke out in trash on a loading dock at the furniture store, would have been contained there had there been sprinklers.
The model showed "the sprinklers activate within 50 to 75 seconds and the fire does not spread beyond the loading dock," Bryner said.
Mayor Joseph P. Riley Jr. said the report gives new weight to the effort to require sprinklers in homes and older businesses.
"An important legacy of the Sofa Super Store fire nationally will give strength to the movement ... for states to more aggressively adopt building codes that have automatic sprinkler standards," he said.
The study was a scientific one, and did not focus on the actions of the firefighters or their leaders, Bryner said.
Attorney Richard Rosen, who represents the owners of the store in wrongful death suits, released a statement saying the store was inspected by the city a little more than a year before the fires.
The study is one of two reports the local prosecutor had been waiting for to determine whether criminal charges may be filed. The State Law Enforcement Division is still investigating the fire, a spokeswoman for the agency said.
A third report by fire experts hired by the city concluded earlier that firefighters did not follow standard safety practices, were under-trained and had obsolete equipment. It also concluded sprinklers would have confined the fire to the loading dock.
The Institute of Standards and Technology will take comments on the draft through Dec. 2 and release a report with final recommendations later.
Bryner said it was the first study the agency had done on a furniture store fire and shows that "furniture stores constitute a unique fire hazard."
The report recommends more aggressive fire inspections by local governments and adoption of model building codes for furniture stores.