America’s biggest cities are slowly collapsing beneath our feet – and most people have no idea it’s happening. A new study reveals all 28 of the nation’s most populous cities are sinking, with millions of residents and critical infrastructure now at risk. The primary culprit is unchecked groundwater extraction, though oil drilling, urban sprawl, and even the sheer weight of buildings are worsening the descent. Houston is sinking fastest, with nearly half the city dropping more than a fifth of an inch per year – some spots twice that. Major cities like Dallas, New York, and San Francisco are also flagged as high-risk zones.