Sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, such as the Minyé sinkhole in Papua New Guinea or Cedar Sink at Mammoth Cave National Park in Kentucky, an underground stream or river may be visible across its bottom flowing from one side to the other. Sinkholes are common where the rock below the land surface is limestone or other carbonate rock, salt beds, or in other soluble rocks, such as gypsum, that can be dissolved naturally by circulating ground water. Sinkholes also occur in sandstone and quartzite terrains. As the rock dissolves,
A Man Walks Into a Bar... A Man Walks Into a Bar... "A Man Walks Into a Bar..." is the 14th episode in the eighth season, and the 176th overall episode, of the American crime drama television series "NCIS". It first aired on CBS in the United States on February 8, 2011. The episode is written by Gary Glasberg and directed by James Whitmore, Jr., and was seen by 20.35 million viewers. In the episode, a naval commander is found dead in his rack aboard ship, apparently murdered. The NCIS team investigates while having to deal with mandatory psychological evaluations conducted by Dr. Rachel Cranston, who