"In a city like New Orleans, where much of the land is already near sea level, even minor drops in elevation can increase flood risk," said Simone Fiaschi — lead author of the study and a former ...

In every city studied, at least 20% of the urban area is sinking – and in 25 of 28 cities, at least 65% is sinking. The nation's biggest cities are sinking, according to data from a new study.