K-19 was a Soviet project 658 nuclear submarine, designated by NATO as "Hotel Class". It was the Navy's submarine that, during its construction and later service, held the sad record of having killed more sailors than any other in the fleet, alluding to an incident on July 4, 1961 received the unofficial nickname "Hiroshima".
It was the first nuclear powered submarine in the Soviet Navy to have ballistic nuclear weapons on board. The three missiles had a range of 650 km and an explosive force of 1.4 megatons of TNT equivalent each.
The boats of Project 658 were of strategic importance for the USSR at the time, as they could carry nuclear weapons all the way to the American coast. ICBMs that could have reached these targets from a greater distance were not yet fully developed at that time.