Pedestrians walk through a farmer's market in the Ballard neighborhood of Seattle, Washington, U.S., on Saturday, July 5, 2014. A place known for hiking and the open spaces of the American West is in the midst of another population boom that's made Seattle the fastest-growing big city in the U.S., bringing challenges such as density, affordability and crime that are more familiar to an East Coast metropolis. Photographer: Mike Kane/Bloomberg via Getty Images