By JO LUTZ Daily Press Staff At exactly 5:26 Monday evening, diners and staff in the Buckhorn Saloon heard a thunderous crash, just before the power went out. “It sounded like a huge crack of thunder,” said chef and proprietor Thomas Bock. “The whole building rumbled.” The time of the incident was preserved on the clock next to the reservation booth, which had not been reset as of Tuesday afternoon, …