Misfortunes in Mexico City never come singly. Built on an ancient lake bed that sinks an average of eight inches a year, the city is also situated on the Ring of Fire, a volatile basin of the Pacific Ocean that produces 90 percent of the world’s earthquake activity. Together, these infelicitous conditions help explain why a 7.1 magnitude quake rocked the city last month — killing 366 and injuring 6,000 — just as an 8.0 quake rocked it exactly thirty-two years ago.

But questions remain. Why, three decades after the devastation of 1985, was the city so badly damaged by an earthquake ten times weaker? Why did forty-four buildings — many of which were constructed in just the last few years — collapse? And why are three thousand more so close to collapse that residents had no choice but to abandon their homes for good?

The answer is that, in Mexico City, the law is a negotiation, and business typically wins. Despite years of reform, the city’s urban planning process still bends away from earthquake preparedness and toward developers’ profits. Slowly but surely, bribes from developers and lax oversight from regulators have undone the city’s resilience.