This week marks two years since a massive 7.0 earthquake surged through Haiti, leaving millions homeless and tens of thousands dead. Survivors could hardly breathe a sigh of relief as they faced disease, debris and aftershocks. The streets were soon lined with bodies. Refugees scrambled for clean water—a rarity even before the quake. Newly leveled ground gave way to tent cities, replete with shacks made of mere sheets and scraps from the aftermath. Many of...