Sinking thumb|upright=1|K-77 reappears on the surface, 25 July 2008 The submarine sank on 18 April 2007 after a storm, and plans were made to raise it off the river bottom. The Museum's theory on why the submarine sank is that a modified hatch was not properly watertight. Recovery efforts by U.S. Navy and Army divers began in June 2008 as part of a project to train military divers through real-world, community-based projects.
Sinking thumb|upright=1|K-77 reappears on the surface, 25 July 2008 The submarine sank on 18 Ap.ril 2007 after a storm, and plans were made to raise it off the river bottom The Museum's theory on why the submarine sank is that a modified hatch was not properly watertight. Recovery efforts by U.S. Navy and Army divers began in June 2008 as part of a project to train military divers through real-world, community-based projects.