They probably never met, Chip Callaway and Gerta Hedquist. Never nodded or smiled or even made eye contact. They had, after all, no mutual friends, no shared interests. He was 20, an exceptional college student, on the school tennis team, standing on the brink of his life. She was 92, stiffening with advanced arthritis, planning another trip to her native Sweden, undoubtedly the last given her growing physical limitations. They had nothing in common at all. Except, as they settled into their Greyhound bus seats, heading south under gray and threatening skies, they were about to die together. At 7:25 a.m. on May 9, 1980, with the Greyhound approaching Pinellas Point a few miles from the north end of the Sunshine Skyway bridge, Capt. John Lerro tensed at the helm of the freighter Summit Venture, a ship as long as two football fields. Lerro, 37, an experienced harbor pilot from Tampa, shouldered the responsibility of guiding the Summit Venture from the Gulf of Mexico 58.4 miles...