Atlanta I-85 collapse: What was underneath?

These images taken from Google Maps Street View show that before Thursday night's collapse of I-85 in Atlanta, stacks of coiled material were stored beneath the interstate where it crossed Piedmont Road. These views are from Piedmont Road looking northeast.

On Friday,  Georgia Department of Transportation Commissioner Russell McMurry described the coiled material as high density plastic conduit that is not combustible, but its exact purpose and properties were not made clear.

PHOTO: The I-85 bridge collapse started with this fire

RELATED: Mystery surrounds construction materials

In the image below from November 2016 — Google Street View's most recent image — the northbound lanes of I-85 are highlighted on the right in red. The area above the coils was the section that collapsed.

According to these images going back to July 2011, the coils were first stored under the interstate sometime between that month and April 2012. The coils don't appear to have moved at all in the five years leading to Thursday's fire.

JULY 2011

APRIL 2012

The area underneath the interstate had a fence, but in most of the images from 2011-2016, the gate is shown to be wide open, sometimes held open by an abandoned shopping cart.

SEPT. 2014 

APRIL 2015 

FEBRUARY 2016

AUGUST 2016

The most recent image from November 2016 shows the gate chained up, but still easily accessible through the gap.