The members of TIME'S Mexico City bureau who reported on the problems and prospects of the world's fastest-growing megalopolis for this week's cover brought to the assignment the survival instincts of megacity veterans. In nine years as a foreign correspondent, Bureau Chief David DeVoss has endured the traffic of jammed Hong Kong, the floodwaters of Bangkok's canals and a tour in war-torn Saigon. Soon after arriving in one of the world's most polluted capitals twelve months ago, he began to fear that the rarefied, contaminated atmosphere was affecting the health of his son, then two years old, logical and technological North Americans," says DeVoss, whose wife is expecting their second child in October, "we soon had our residence humming with air cleaners and humidifiers. But no matter how much I may complain about this place, I find the feeling of history very strong, and I wonder if what may seem like underdevelopment to the foreigner is not actually what makes this city so intriguing."

Correspondent Ricardo Chavira visited there often while growing up in Los Angeles. "Even on my first visit to Mexico at age ten," he says, "I felt that despite its size, noise and disorder, the city worked. Ever since, I've been impressed with how well it has coped with its enormous growth, and I can't help being optimistic about its future." Even more optimistic is Bureau Manager Andrea Dabrowski, whose mother is Mexican and father American; while this week's story was being reported, she was choosing between U.S. and Mexican citizenship. For Dabrowski, who has lived in Mexico for most of the past 24 years, the choice was difficult, but, she says, "whenever I leave Mexico City, I breathe in relief for the first few days. But I always come back. As the plane approaches and I see the smog clouds, I begin to feel at home, and I love it." The cover story is the work of Senior Writer Otto Friedrich, author of TIME'S 1982 report on another storied city, Jerusalem. Before writing the articles, he visited his subject cities to savor some local color and test his presuppositions. "In both Jerusalem and Mexico City, I was much more impressed by their great age than I was prepared to be," says Friedrich. "Both cities are also much more complex, demographically and culturally, than I had thought. I expected to find Mexico City a Hispanic city, for example, and was surprised by the strength and visibility of its Indian culture. And of course, one cannot visit either place without being struck by its beauty. Spending time in Mexico's capital furnished me with the perspective to turn a bunch of pollution statistics into a story of a great city in trouble."