Congested Mexico City must look skyward to grow

Once the heart of the vast Aztec empire, Mexico's pulsing capital is now a megacity that dominates the country's economy, politics and culture, but it must take drastic steps to tackle its dwindling water supply and crippling transport problems, said the official charged with making the city resilient.

Megacities like Tokyo should be a development model for earthquake-prone Mexico City, which needs to grow upwards rather than continue its urban sprawl, said Arnoldo Matus Kramer, chief resilience officer for the city that is home to nearly 9 million people, with over 21 million in its greater metropolitan . . .