SALEM, S.C. (AP) — An 83-year-old woman who died when she fell through rotting floorboards in a century-old South Carolina house and down a well shaft the owner didn’t know was there, authorities said.

It took rescuers nearly four hours Sunday to get the women’s body out of the nearly 50-foot (15-meter) deep hole, Oconee County Coroner Karl Addis said in a statement.

The woman was helping her daughter pack up and move from the house in Salem, which according to property records was built in 1920, Addis said.

As she walked across the kitchen floor, part of it collapsed. The woman’s daughter searched for her in the crawlspace under the house and couldn’t find her, according to a police report.

Firefighters finally were able to find the woman and bring her bock back to the surface, said the coroner, who determined she died from injuries from the fall.

Addis declared the death an accident and said he has never seen a death like this in his 31 years as coroner in Oconee County, which is about 40 miles (64 kilometers) west of Greenville.