LONDON — With overhead power lines strung between large metal towers, polluted waterways, old scrap yards, abandoned factories, piles of used cars, and heaps of discarded refrigerators, east London once looked like a dystopic wasteland. It seemed hopelessly blighted and permanently scarred by industrialization.

Then, London landed the 2012 Summer Games. And, thanks to roughly $10 billion out of an estimated $15 billion-$20 billion Olympic budget, everything changed in the East End.