On this day in 1927, a Navy submarine, S-4, and a Coast Guard cutter collided within sight of Provincetown. The cutter's bow sliced into the submarine's hull, sending it to the bottom of the bay within minutes. The Coast Guard and Navy immediately dispatched rescue ships and divers, but a growing nor'easter and treacherous underwater currents thwarted their attempts to rescue the six trapped survivors. By the time divers reached them again four days after the accident, all six had died. The failed rescue attempt got international media coverage, and an inquiry followed. To the outrage of many, only the captain of the submarine was held responsible for the tragedy. However, subsequent improvements in rescue equipment helped save lives in later sea disasters.