LUBBOCK — Desmond Bemiss stood at the open doors of the yellow school bus and watched three of his children get aboard for their first day of school. Bemiss had been up since 5 a.m. His 5-year-old daughter, Dachannice, woke him as she often did in their home on Urseline Street in New Orleans. None of the Bemisses, 20 of them in all, had slept much the night before or the nights before that. Even when some of the lights were turned out, the conversations, televisions and boom boxes made the old Air Force hangar roar again into the early...