ATLANTA -- A massive fireball collapsed a portion of Interstate 85 in Atlanta, sending motorists driving through billowing black smoke before the city shut down that section of the highway indefinitely.
The fire started underneath part of the highway on Thursday evening. At about 7 p.m., an elevated section of the northbound interstate collapsed, forcing frantic motorists to seek alternative routes.
Inspectors now say both sides of I-85 will have to be replaced as both were damaged.
An estimated 250,000 cars per day drive through that stretch of the interstate -- a major thoroughfare for traffic heading north and south through Atlanta.
While the highway is normally jammed with cars around that time, there were no fatalities, Mayor Kasim Reed said.
What caused the collapse?
As word of the incident spread, so did the speculation.
Atlanta Mayor Kasim Reed did not provide details on what caused the collapse, but said it is not linked to terrorism and an investigation is underway.
"We've spoken to the special agent in charge of FBI, there is no evidence this is related to terrorism," he said Thursday night.
Gov. Nathan Deal said he heard speculation it was caused by some "PVC products that caught fire."
In an unusual move, two fire trucks from Hartsfield-Jackson Atlanta International Airport in south Atlanta rushed to the scene and sprayed foam on the fallen section and flames.