It's not a pleasant process, but a catastrophic failure would be ideal from a "way to go" standpoint.

By comparison the USS Thresher had a small brazing leak, followed by a freezing of the compressed air they tried to fill the ballast tanks with to emergency surface, and then got to experience the bulkheads imploding and slowly be crushed as they sank. There's audio from nearby ships of it imploding online and it's pretty terrifying to listen to.