Piedmont Road, a main surface street passes underneath the elevated I-85 at that point. All the PVC and fiberoptic cable was stored underneath the elevated interstate. There's not much free area there due to the old I-85, now called the Buford Hwy-Spring Street Connector that runs parallel and Peachtree Creek which runs parallel on the other side.
One of our former members who lives downtown originally thought it was construction materials for a nearby apartment complex. It isn't unusual for materials to be stored underneath bridges, especially if it relates to highway work. At our famous Spaghetti Junction at I-85 North and I-285, there are large Quonset buildings underneath and adjacent to supporting columns that are over 100 feet tall.
The Connector has been reopened, so that is taking some of the load off the surface streets, and I-85 has been reopened from Spaghetti Junction down to the last exit before the damaged area. That puts Southbound traffic onto the Connector or Piedmont Road, either side of the damaged area.