NEW YORK, New York (AP) -- Investigators believe a fire fed by diesel fuel stored in 7 World Trade Center may have led to the building's collapse, according to a published report.

The fire, which was ignited by falling debris from the burning twin towers, raged for about seven hours before the 47-story building collapsed on Sept. 11.

According to a preliminary report, the fire may have caused a group of steel beams that supported the skyscraper - called ``transfer trusses'' - to fail, The New York Times reported Saturday.

The findings were detailed in a preliminary report by a team of engineers organized by the Federal Emergency Management Agency and the American Society of Civil Engineers.

The report was based on video footage, debris, structural analysis and interviews with firefighters and witnesses. Researchers cautioned that the conclusions could be modified as the investigation continues.

The office tower, which stood across Vesey Street just north of the World Trade Center, housed former Mayor Giuliani's emergency command center and other government agencies, including offices for the Secret Service. The bridge-like transfer truss structure allowed the building to be constructed above an already existing power substation.

The diesel fuel that investigators believe may have fed the fire was stored in large tanks near ground level and in smaller tanks and emergency generators for the command center, the Secret Service and other tenants, The Times said.

Irwin Cantor, one of the building's original structural engineers, said the report's findings provided a reasonable explanation for the collapse. He said he did not think the diesel fuel tanks were included in the building's original design.

``It ended up with tenants who had diesels,'' Cantor told The Times. ``I know none of that was planned at the beginning.''

But Frank Lombardi, the chief engineer for the Port Authority, which owns the property that the tower was built on, told The Times that according to floor plans, the building complied with city fire codes.

Jerome Hauer, who was the director of Giuliani's office of Emergency Management when the emergency command center opened, said several engineers had reviewed the plans.

``There were lots of people that looked at this,'' Hauer told The Times. ``We relied on their judgment.''

The failure of a structural feature similar to the transfer trusses at 7 World Trade Center contributed to the collapse of the Alfred P. Murrah Federal Building in Oklahoma City, The Times said.

Federal guidelines for public buildings created after the Oklahoma City bombing warned of the dangers of similar trusses in terrorist attacks, the newspaper said.