ON THIS DAY: 10th September 1509 - An estimated 10,000 people died in Constantinople due to an earthquake so strong it was known as "the Lesser Judgement Day". The 1509 Constantinople earthquake, referred to as "The Lesser Judgment Day" (Turkish: Küçük Kıyamet) by contemporaries, was an earthquake that occurred in the Sea of Marmara on September 10, 1509 at about 10 p.m.. The earthquake had an estimated magnitude of 7.2 ± 0.3 on the surface wave magnitude scale. Forty-five days of aftershocks followed the earthquake, as well as a tsunami. Over a thousand houses and 109 mosques were destroyed, and an estimated 10,000 people died.
Source: Wikipedia