Sinkhole swallows pond, Residents were very concerned after a sinkhole swallowed up a pond on Sunday stunning local residents in Newcastle, California. Local landowner, Mark Korb, has said he woke up on Sunday morning only to find the man-made pond on his land had completely disappeared, apparently it had drained away due to a massive sinkhole beneath the land. The sinkhole managed to drain the entire pond just overnight, with Korb saying, "I would guess probably four to five hours for this whole area to drain." The report comes just weeks after two massive sinkholes in Florida stunned the nation, with one of them swallowing up a man as he lay in his bedroom. So what are sinkholes and how do they occur? Sinkholes are basically depressions in the ground that form over time due to the combined forces of erosion and gravity. They have been known to reveal themselves gradually over time, although sometimes, like the cases in Florida, they can cause sudden collapses. Scientists s