What happens when a city experiences explosive growth and balloons into a vast metropolis? That's what happened to Karachi, Pakistan which has grown from 400,000 people in the 1940s to more than 13-million people today. NPR's Morning Edition co-host Steve Inskeep talked to KPLU's Kirsten Kendrick about the growing pains of one of the world's fastest-growing cities which is the subject of his new book, Instant City - Life And Death In Karachi.