DETROIT—The childhood home of former Massachusetts Governor Mitt Romney in northwestern Detroit was torn down Tuesday as part of an effort to level thousands of vacant properties in the city. Wrecking crews leveled 1860 Balmoral Drive, the boyhood home of Mr. Romney, following the removal of several large trees that had delayed the home's demolition for weeks.......following years of complaints from neighbors, Wayne County declared it "a public nuisance and blight"...