BOSTON (AP) — A former U.S. Marine held in Russia for more than four years on disputed charges is gravely ill and at risk of dying, his family and advocates said Friday. His mother flew to Russia a couple of weeks ago in an attempt to see him, Lebson said, but hospital officials denied the visit. U.S. Sen. Edward Markey called on Russia and the U.S. to work together to get the Massachusetts resident released. A spokesperson for the State Department said it was “deeply concerned about Robert Gilman’s health and continued detention in Russia.” The business daily Kommersant reported that Gilman pleaded guilty to the charges and apologized to the guards he was charged with assaulting.