Repairs began Thursday on a sinkhole that opened up near U.S. Highway 127 north of Pikeville, Tenn., on Wednesday, officials said.
The gaping hole exposed at least one water line, an apparent underground stream and could have threatened the roadway if it had grown, officials said.
The repair work consists of filling in the bottom of the hole with large rocks, then "continue filling the hole with rock that will get progressively smaller until the sinkhole is completely filled and shored up," Tennessee Department of Transportation spokeswoman Jennifer Flynn said. The repairs might be completed in a day, she said.
Flynn said the hole was discovered by a TDOT maintenance worker who reported the find to the district maintenance supervisor and state geotechnical officials in Nashville. Officials monitored the hole until crews started repairs, she said.
"It's a very deep hole. It's approximately 30 feet deep," Bledsoe County Mayor Bobby Collier said on Thursday.
The water at the bottom of the hole appears to be an underground stream, Collier said.
To address worries that nearby, recently placed water lines might be leaking, utilities officials tested for chlorine but found none in the water at the bottom of the sinkhole, Collier said.
Positive tests for chlorine would indicate that treated drinking water was leaking, he said.
Collier, a former agriculture teacher, said he believed the soil simply was reacting to dry conditions and periodic heavy rains. He said heavy equipment used to install the water lines a couple of months ago might have contributed, but he said that was just speculation.
"It's well-drained soil," he said. "We were very lucky nobody got hurt. I think the tractors that mow the rights-of-way had mowed over it just two days before."
Flynn said sinkholes are fairly common in Bledsoe because the "mountainous geology" of the area makes it prone to sinkholes and rock slides.