The first people to come to Venice were refugees from Roman cities. Venice was easy to defend because there was water all around it. Soon, Venice became the centre of international trade and art. Rich people built beautiful homes, bridges and churches there. But then, Venice started sinking because industry and agriculture were using the water from under the city. Today, there are more floods in the city than ever before because of the high tides. Many Venetians have left the city because of the flooding and also because tourism has made food and property very expensive. Venice is in danger of disappearing because of the higher water levels and the smaller population.