Plan view and profile drawings of Bering Sinkhole. When work began in 1987, the sinkhole was filled to within about 10 feet from the surface. But the fill layers containing the human remains were deeper. The drop from the entrance to the sinkhole floor during its use as a cemetery would have been between 5 and 7 meters (approximately 16 to 23 ft.). From Bement 1994, Figure 2.