Mystery surrounds materials stored beneath interstate,

Google Maps photos first show stored items in April 2012.

The surplus construction material under the I-85 overpass that collapsed Thursday in Buckhead had been stored there for many years, Georgia Department of Transportation Commissioner Russell R. McMurry said Friday.

McMurry said the material was a high-density plastic conduit used for cabling and fiber optic wire networks. He said GDOT was trying to get a fix on exactly how long the material had been there, and suggested it could be as long as 11 years.

It “is not uncommon for any other state to store things under their bridges,” McMurry said.

But photos from Google Maps show the site was clear of any stored material in July 2011.

The materials first show up in Google Maps photos in April 2012 and appear to be untouched through the most recent photo taken in November 2016.

McMurry compared the material to having a “plastic cup in your cupboard.”

“It does not ignite,” McMurry said. “It takes something to cause something like that to burn. It is a high-density plastic that is not combustible.”

When asked if his agency was ever ordered to remove the materials, McMurry said: “I’m not aware of such a notice being given, or the reason why it should be given.”

GDOT officials have said the area was secured, but Google Maps photos show the area was protected only by a chain-link fence with a double gate that was sometimes left open. Even when locked, it would have been possible to slip in between the gates or climb over the fence.

Atlanta Fire Chief Joel Baker said he’s not sure what temperature is required to cause a collapse, but said the plastic materials caused it to get that hot.

“The amount of plastic and other materials, there was a lot,” Baker said. “I don’t know how much tonnage was involved. But due to the material involved, it generated a whole lot of heat to cause that to happen.”

McMurry only answered a handful of questions during a Friday press conference.

GOOGLE MAPS STREET VIEW This November image from Google Maps Street View shows the underneath of I-85 where the interstate passes over Piedmont Road, looking to the northeast. The section that collapsed is above the stacked coils of material seen at right.