The National Transportation Safety Board has released its report into last year's bridge collapse along Interstate 85.

The report suggests a Georgia Department of Transportation decision contributed to the collapse.

While the report said the NTSB doesn't assign blame for an incident and talks about fact-finding, it does say under probable cause that a GDOT decision contributed to the bridge collapse and it basically alleged a failure of risk-assessment.

[Special Section: I-85 Bridge Collapse]

The NTSB said the probable cause for fire was "excessive heat from the ignition of 76 reels of high-density polyethylene conduit and nine racks of fiberglass conduit stored beneath the overpass. Contributing to the bridge collapse was the decision of the Georgia Department of Transportation to store construction materials beneath the bridge and its failure to assess the increased fire risk due to the presence of these combustible materials."

[READ: Those who helped rebuild I-85 after collapse look back on lessons learned 1 year later]

"If there had been an injury or a life lost, I mean just … that's just unimaginable to me the situation we'd be in," GDOT Commissioner Russell McMurry told Channel 2's Aaron Diamant last month.

A statement from GDOT said in part, "last year, GDOT made changes in its storage practices within hours after the bridge collapse and we remain committed to building on the changes we have already implemented, which specify no storage of flammable or combustible materials under bridges."  

“Plastic products are petroleum based and basically when it starts heating up, it starts deforming from a solid to a liquid and once it becomes heated up to a certain temperature, it becomes basically a liquid fire. Three-dimensional fire is what we call it and it flows,” Georgia State Fire Marshal Dwayne Garriss said.

[READ: 1 year since Atlanta's infamous I-85 bridge collapse]

The GDOT statement also said, "We fully participated in the preparation of this document. We are hopeful that these recommendations from the NTSB will be instrumental for other relevant agencies and Departments of Transportation across the country to prevent instances like this from happening elsewhere."

Police have said Basil Eleby, a homeless man, was using drugs under the bridge when he set fire to a chair on a shopping cart and the fire spread to high-density plastic conduit stored under the bridge.

Eleby was charged with arson, but his case was transferred in December to Fulton County's Behavioral Health Treatment Court. The charges against him will be dismissed if he completes a mental health court program.