Thus, the naive Candide and his philosopher-master Pangloss get instructively caught up in the Lisbon earthquake, an event of such destructiveness – 30,000 dead – and of such philosophical and theological aftershock as to make 9/11 look like a minor incident. This disaster had occurred as recently as November 1755; while the Inquisition's response to the calamity, that of an auto-da-fé designed to prevent further earthquakes (the heretic-hunt sweeps up Candide and Pangloss) took place in June 1756.
Look up later about earthquake.