I just checked for the statistical odds of Adams and Jefferson both dying on July 4, 1826 and according to an
ARTICLE in Forbes, it is 0.0000657 or just seven chances in 100,000. And that did not factor in the significance of that date being the 50th anniversary of the Declaration of Independence.
And now someone has to figure out the chances of the fifth president dying on July 4 exactly five years later. Get it? FIFTH president FIVE years later. And the odds get much much longer.