Three arrested in fire that caused I-85 collapse in Atlanta.

On Thursday, a blaze — which started in a state-owned storage lot under an interstate highway in Atlanta — caused part of northbound I-85 to collapse, forcing the closure of all five lanes for the foreseeable future.

Three people — all believed by investigators to be homeless — have been arrested on suspicion of intentionally setting the fire. Investigators are still working to determine how the fire started.

Dozens of firefighters battled the roaring blaze for nearly an hour; they were moved safely out of harm’s way amid telltale signs the roadway was breaking apart from the intense heat. In a metro area known for gridlock, the collapse has officials scrambling for solutions. Things aren’t expected to be back to normal for months.

The highway’s closure also comes as hordes of spring break vacationers are expected to drive through the region’s urban hub. The collapsed span was built in 1953 and renovated in 1985.

David Goldman / Associated Press Smoke billows from a section of an overpass that collapsed from a large fire under Interstate 85 in Atlanta. Georgia officials say repairing damaged sections of I-85 north of downtown Atlanta will take months.