Geologist: Poor infrastructure could be to blame for 17-foot deep Chattanooga sinkhole

CHATTANOOGA, Tenn. — UPDATE (Friday):

On Friday, crews filled in the sinkhole that opened up in the parking lot of a Chattanooga-area Walgreens, but the question remains - what caused its collapse?

Geologist Amy Brock-Hon studies ground materials in the Hamilton County area. She says lots of wet weather can weaken the limestone in the ground.

"If you have rainfall and vegetation and it's moving through limestone in the subsurface, you can develop voids, caverns that could lead to collapse under the surface causing sinkholes," says Brock-Hon.

But more likely, she says its something man-made underground that caused the hole.

"Oftentimes if there's a leak in one of those pipes, it can cause erosion in the material in the subsurface," says Brock-Hon, "Or sometimes it might be the case of just a pipe collapsing and that can cause the surface material to collapse."

Crews from Sequatchie Concrete Services say this is only a temporary fix.

Friday, we saw a pipe still leaking from inside the hole.

We reached out to the city to see if that pipe is their responsibility. They told us that because it's on commercial property, it's Walgreens' responsibility to fix it.

Just last summer, the city shut down parts of Broad Street for a major drainage system improvement project not far from where this sinkhole sits tonight.

But the city says that project is not related to this new problem.

PREVIOUSLY (Thursday):

Officials are taking in the damage after a sinkhole opened up in the parking lot of a Chattanooga Walgreens.

It happened at the Walgreens at 3550 Broad Street Thursday.

NewsChannel 9's Taylor Stewart is on the scene.

Officials told her the sinkhole is about 17 feet deep, and 18 feet wide - that's large enough to swallow a small car.

The scene has been cordoned off as officials investigate.

A city spokesperson says an engineer should take a look a the damage Friday.

Depend on us to keep you posted as we learn more.