November 1, 1755. Shortly after the Lisbon earthquake struck the great city, a series of huge tsunami waves crashed over the harbor quays, engulfed the lower part of Lisbon on the shore of the Tagus, and submerged much of the lower part of the city including its newly built, marble quay of Cais De Pedra which disappeared into the river. The first three of these tsunami waves were the largest and completed the destruction brought about by the two earlier strong quake shocks. 20,000 more of the terrified survivors who had rushed to the open space of the docks and the waterfront quay for safety, lost their lives to these tsunami waves. All boats moored in Lisbon's harbor were destroyed.