NTSB Issues Reports on Protecting Bridges from Fire Damage and Collapse (NTSB)
On Thursday, March 30, 2017, about 6:05 p.m., construction materials stored under an Interstate 85 (I-85) overpass in Atlanta, Georgia, were set on fire. The fire propagated throughout the storage area. Just over 1 hour later, at 7:14 p.m., span 30 NB—a 92-foot-long elevated span of I-85—collapsed. No fatalities or injuries were reported from the fire and subsequent bridge collapse. One person was arrested and later charged with criminal damage to property. The Georgia Department of Transportation (GDOT) had been using the area as storage for 76 reels of high-density polyethylene conduit and nine racks of fiberglass conduit. The materials were left over from an earlier project on State Route 400 (SR-400) and were secured inside a chain-link fence.
The National Transportation Safety Board determines that the probable cause of the fire and subsequent collapse of the span 30 NB bridge structure on Interstate 85 north, in Atlanta, Georgia, 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.