The website, developed by the Department of Environmental Protection, will allow owners of more than a million affected homes to check whether they are above or near an abandoned mine.

“Each year, we see homes crack, tilt or collapse as old mine workings give way,” DEP secretary Kathleen McGinty said.

“Most home owners’ insurance policies do not cover damage caused by subsidence or the flooding that occurs after underground mine pools burst through the surface.

“Mine subsidence insurance is an inexpensive way to guard your lifetime investment.”

Coal has been mined underground in Pennsylvania for more than 200 years and the workings extend through 43 of the state’s 67 counties.

Since the creation of the Mine Subsidence Insurance (MSI) fund in 1961, administrator DEP has paid more than $US20 million in claimed repairs.

The new website (www.paMSI.org) enables residents to view maps of municipalities in Allegheny, Butler, Blair, Cambria, Clarion, Fayette, Greene, Indiana, Washington and Westmoreland counties, where mine subsidence problems are acute.

Residents in those counties can identify their neighbourhoods to determine whether mining took place there and decide whether insurance is needed.