Feds Dive Into Big Dig Sinkhole Saga

Photo by Matthew West

.......  DePaola has blamed the suspected sinkhole under the tunnel and the compression of soil under train tracks serving South Station — an ongoing problem that has forced rail workers to prop up the track beds with 8 feet of ballast in recent years — on a greater than anticipated degree of settlement of the soil as it thaws out after a massive ground freezing project in 2000........  WHOLE ARTICLE: http://www.bostonherald.com/news/regional/view.bg?articleid=1361487