A routine gas line installation on West Broadway in Jim Thorpe last month uncovered something that surprised even some borough officials: a hole in the roof of the tunnel that carries Mauch Chunk Creek directly beneath the sidewalks of one of the most heavily visited streets in Carbon County.

The discovery was made when UGI crews, working to install a gas lateral into a home near 62 W. Broadway, pulled up a pavement slab and spotted the opening in the tunnel ceiling under the adjacent slab.

“There’s a hole in the roof of the tunnel, a small hole,” Council Vice President Mike Yeastedt told colleagues Thursday during the borough’s monthly workshop. “It’s under the adjoining slab. We didn’t want to take the slab out until we knew what we would do about it.”

Many people, including borough officials, had not known the tunnel ran that particular route.

“Unbeknownst to many people, including myself, when it crosses West Broadway, we kind of thought that it went down behind the houses,” Yeastedt said. “But in fact, it doesn’t. It pulls right in, and it’s directly underneath the sidewalks for a period of houses, and then it veers back toward Hill Road and rounds the Opera House.”

Mauch Chunk Creek has flowed through a tunnel beneath the streets of Jim Thorpe since the town’s earliest days as the coal-shipping center known as Mauch Chunk.

As far back as the mid-1800s, the National Register of Historic Places noted that the creek had been “confined to a culvert under the street and buildings at an early period” because the valley was too narrow to accommodate both the growing town and an open waterway.

Borough officials reached out to PennDOT, which controls the road surface above, but the sidewalk, not the road, is where the hole sits.

“Since it was in the right of way of PennDOT, we reached out to PennDOT and asked them if they were responsible,” Yeastedt said. “Which, of course, they were not. So it falls back on us.”

Whether “us” means the borough or the adjacent property owners is itself an open question.

Borough Manager Maureen Sterner said the solicitor still needs to weigh in.

“We still need a determination from the solicitor, because it’s in the sidewalk,” Sterner said. “Is it the borough’s? Is it the property owner’s? Or is it PennDOT?”

Whatever the answer, Sterner made clear the physical problem cannot wait indefinitely.

“Regardless, something needs to be done,” she said. “It needs to be looked at. It needs to be addressed.”

The pavement slab covering the hole remains in place for now. The next step, officials said, is removing the slab so an engineer can assess the extent of the damage and determine what kind of repair is needed.

“We would like an engineer to look at it once the slabs are removed and say yes or no — can it just be a matter of putting some mesh and concrete in there, or is there something more required?” Yeastedt said.