A 72-year-old woman died of natural causes in a tightly locked house on 25 acres in rural South Carolina.

And for 18 months, nobody knew the reclusive widow was gone.

Only after Calhoun County deputies found the remains of Mary Sue Merchant last Thursday did it occur to her Sandy Run neighbors they hadn't seen her in awhile.

The discovery came after her home was sold for unpaid 2008 property taxes. A local real estate agent who bought the property for $20,000 asked deputies to check because her car never moved.

By all accounts, Merchant and her husband kept to themselves. They had no children.

David Merchant died in 1985, and Calhoun County Coroner Donnie Porth is trying to track down her older sister in California. A sister-in-law lives in Newberry.