Six-year-old twins who were critically injured when a fire tore through a Bronx apartment building and killed their 1-year-old brother last week have since died, according to the devastated parents forced to bury all their children. Father Kwesi Harris confirmed to The Post from a funeral home on Monday that his 6-year-old children, Isis and Oseases Parks-Harris, died from injuries they suffered in a blaze that erupted at their building on Bainbridge Avenue last Monday. His 1-year-old son, Liam