WADSWORTH, Ohio (AP) — Some residents in a northern Ohio city are being forced to leave their homes after the structures began sinking into the ground.

Wadsworth officials say four condominiums and a nearby house are unsafe and notices have been posted instructing the owners to vacate. Homeowners have reported cracks in their ceilings and collapsed walls.

A spokesman for the Ohio Department of Natural Resources tells WEWS-TV the cause hasn't been determined, but he believes the damage is due to an abandoned mine shaft that collapsed nearly 85 feet (25.91 meters) below the ground.

Wadsworth Director of Public Service Robert Patrick says a coal mine subsidence study was done before construction began at the condominium development.

Wadsworth is about 40 miles (about 64 kilometers) south of Cleveland.