Texas authorities, tipped off by a concerned meter reader, yesterday found a sister and brother, ages 11 and 5, living alone inside a broken-down school bus on a lot teeming with garbage. The children had been living on the bus, which apparently had been altered to have electricity and water, for three years. But their parents went to federal prison a few months ago, and an aunt says she has been coming to the bus at night to feed the boy and girl since then. They were also reportedly home schooled, KTRK reports, but it's not clear who taught them. The children are now in foster care, and a custody hearing is set for today.