John Allen suffered a fatal heart attack on the evening of January 6, 1973. He had previously suffered at least one heart attack during the 1960s. Although he was not feeling well, he worked at completing the Gorre & Daphetid. In a telephone conversation with Linn Westcott, he suggested that he would drive the last spike in the spring of 1973, and that Linn should come for a visit then. In 1972, he was already suggesting that things might not be going well, and wondering "what to do with the railroad" in letters to a friend.