Courtesy of Scientific American
The Titanic Struck a Glancing Blow Against an Under-water Shelf of the Iceberg, Opening Up Five Compartments. Had She Been Provided With a Watertight Deck At or Near the Water Line, the Water Which Entered the Ship Would Have Been Confined Below That Deck, and the Buoyancy of That Portion of the Ship Above Water Would Have Kept Her Afloat. As It Was, the Water Rose Through Openings in the Decks And Destroyed The Reserve Buoyancy