AMATRICE, Italy – Rescue crews using bulldozers and their bare hands raced to dig out survivors from a strong earthquake that reduced three central Italian towns to rubble Wednesday. The death toll stood at 159, but the number of dead and missing was uncertain given the thousands of vacationers in the area for summer’s final days. Residents wakened before dawn by the temblor emerged from their crumbled homes to find what they described as apocalyptic scenes “like Dante’s Inferno,” with entire blocks of buildings turned into piles of sand and rock, thick dust choking the air and a putrid smell of gas. “The town isn’t here anymore,” said Sergio Pirozzi, the mayor of the hardest-hit town, Amatrice.