India, Dec. 10 -- A month on, the silence inside the Kataria home feels as heavy as on the day of the blast. The grief is pervasive, in the way Amar Kataria's wife, Kriti, clutches his cellphone as if it were a lifeline, to how their three-year-old son points to his father's photograph and says, "Papa photo ho gaye hain." Kriti, 32, barely sleeps, her father-in-law says. The phone - one of Amar's two devices retrieved after the blast - rarely leaves her hand. She has tried to occupy her days with online tutoring, but that is only fleeting distraction. Their son, Viaan, will now know his father through photographs. For Amar's father, Jagdish, the loss is a blow that goes beyond the emotional. At 33, Amar had built a thriving wholesale medici...