Updated

Part of Interstate 85 collapsed north of downtown Atlanta Thursday night after a massive fire broke out under the busy highway during afternoon rush hour traffic.

The fire broke out at around 6 p.m. Atlanta fire officials told Fox 5 the blaze caught giant spools of plastic utility conduits which were being stored under the overpass.

No injuries to motorists or firefighters were reported. Georgia State Patrol Capt. Mark Perry told the Atlanta Journal-Constitution that terrorism is not suspected.

Prior to the collapse, structural engineers told FOX 5 they were worried about fire melting the metal under the bridge. Witnesses say troopers told motorists to turn around on the bridge because they were concerned about its integrity.

The bridge collapsed at around 7 p.m. Foam trucks were eventually brought up from Atlanta's Hartsfield-Jackson International Airport to smother the remaining fire.

"We do have the fire under control," said Sgt. Cortez Stafford, a spokesman for the Atlanta Fire Department.

"The part that is not contained is the part that is under the section of the bridge that has collapsed," Stafford said, adding that he does not expect the blaze to spread to any other structures.

The department warned all motorists to stay off I-85. Alternate routes include taking I-75 to I-285 or I-20 to I-285.

Multiple media outlets report traffic was bumper to bumper on Buford Highway as people tried to escape the backup from the collapse.

Georgia Gov. Nathan Deal said state Department of Transportation inspectors had been called to the scene and the construction crew that built the bridge was determining how long repairs would take.

"We're trying to determine everything we can about how quickly can we repair it and get it back in service," Deal said. "I can assure you we will do everything to expedite the repair and replacement of that section of the bridge."

"It got dark all of a sudden so I turned on the news to see if it was the rain," Paula Pontes, a resident of the Buckhead neighborhood, told the Journal-Constitution. "I didn’t panic because I couldn’t see the fire coming. It was just smoke. It became night."

The Associated Press contributed to this report.

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