The problem is the worst in the busy financial center, where there are huge skyscrapers on what was farmland not long ago. A report says that land there sank nearly four centimeters last year. Land around the tallest building sank nearly six centimeters. Officials started to record changes in 1921, and they believe the city has sunk nearly two meters since then. There are similar problems in Bangkok and Mexico City, and the people of Shanghai need to to understand that construction must slow down. The officials hope show them how bad the problem is. However, with so many buildings already up it may be too late.