UPDATE: The cause of a July train derailment in Spring City has been released.

A Norfolk Southern spokeswoman told Channel 3 on Saturday the preliminary investigation shows a defective wheel on a privately owned coal car caused the rail to break and the cars to derail.

Norfolk Southern train cars were carrying about 5,800 tons of coal. 

The crash took out some power lines leaving nearly 500 homes without power. Highway 27 was partially closed while they worked to clear the scene. 

The roadway was opened back up the next morning. No injuries were reported.

The cleanup effort continues in Spring City, where crews are still working to clear the wreckage from a massive Norfolk Southern train derailment.

Workers rushed to repair the track, and were able to re-open it on Saturday night.

Mangled cars still line the tracks in the center of town.

"When you see the wreckage, the first thing that comes to your mind is, like, it could have been so much worse," said James Gilbert of Spring City.

On Thursday night, 49 cars, carrying 5,800 tons of coal, went off the tracks.

Crews have been working nonstop ever since.

"Friday, I mean, there was no way you would've ever thought that there were gonna be any trains coming through for a while," Gilbert said. "Then here we are on Monday, and we've already had trains coming back through."

According to Rhea County Emergency Management Agency, workers will likely be on site, making repairs through the week.

Several downtown roads are still blocked.

"It's been a bit of chaos, traffic-wise, with a lot of people having to route around," said Jeff Bowers, Spring City resident.  

The train derailed in the center of the town's business district, nearly missing the Historic Depot.

"When you think of Spring City, that is our symbol. So we're very happy nothing happened to that," Bowers said.

Residents are also relieved the coal spill wasn't hazardous to the environment or anyone's health.

"We're all thankful," said Bowers, "and we're all very blessed that nobody was hurt."

"I think the whole town realizes that," Gilbert added."It could have really been bad, but it wasn't. We got lucky."

Crews are having to close the track sporadically as repairs continue. Norfolk Southern's website says customers should expect delays until normal operations resume.