Pennsylvania Town Going Down, Down : Leechburg: Extensive coal mining causes the ground to sink. That’s bad news for buildings and residents. State tries to plug up the problem.

Little by little, this pleasant river town is cracking up.

Foundations are sinking, doors and windows are refusing to close and basement walls are sprouting hairline fissures.

The problem is mine subsidence: the settling that occurs after a swath of coal has been removed, often from 100 feet or so beneath the earth’s surface.

“It’s terrible,” said Rosa Mussano, pointing at cracks zigzagging along the cement blocks of the foundation of her yellow clapboard house.

“I’m afraid to lock my kitchen door, because if I lock it I might not be able to open it again,” said Mussano, 76.

The problem isn’t being ignored. For the last four years or so, workers hired by the state have been plugging up the cavities with a mixture of fly ash, cement and sand, hoping to prevent more settling.

The project’s third phase, which began in February, is expected to be finished by the middle of December. Already, about 50,000 tons of “grout slurry” have been pumped underground as part of this phase, which will ultimately shore up about 95 homes, according to Rich Campbell, project inspector with the state Department of Environmental Protection.

One recent morning, workers with Howard Concrete Pumping Inc. dumped black fly ash into large metal bins. A conveyor belt carried piles of the ash to a mixing pot, where it was combined with the other ingredients. The slurry gurgled through a long pipe to a 70-foot-deep hole in a back yard two blocks away.

“The idea is to fill as much of the mine back up again as possible,” said Campbell, as the pipe jerked with the motions of the distant pump.

The work is welcomed by people in this cheerful town of 2,000 or so, cradled in an elbow of the Kiskiminetas River about 30 miles northeast of Pittsburgh.

But it hasn’t put to rest fears about damage to houses, one of which had to be torn down.

Councilman Anthony E. Del Vecchio counts himself among the lucky ones--his house hasn’t yet been affected by subsidence. But he has seen the “good-sized” cracks in the basements of two neighbors.

“One fellow had to have a whole new foundation and a new cement floor put in,” he said. “There was a pretty good cave-in.”

Nearly everyone has something to worry about. The Upper Freeport Coal Seam--the layer of coal that once extended under about two-thirds of the town--has been mined almost completely, according to Campbell.

“When people say, ‘Do you think it’s underneath my house?’ you have to say yes,” said borough secretary Carol Defilippi.

Although the settling has worsened in recent years, subsidence isn’t new to Leechburg, where coal-mining began in earnest after the Civil War and didn’t stop until the middle of this century.

Back in 1932, one of the nicest houses in town suddenly sank a yard, said Bob Fiscus, a retired postmaster.

“It just dropped down,” said Fiscus, 70. “You lost the cellar.”