Most of us make retirement plans with the best-case scenarios in mind. But what happens when those carefully laid plans are upended by tragedy? Imagine David, a 60-year-old man who retired seven years ago. He's living on around $1.5 million in retirement funds and had planned to take Social Security at 67. But then his younger sister died, leaving him to care for her two teenage daughters, ages 13 and 16. Must Read Thanks to Jeff Bezos, you can now become a landlord for as little as$100 — and no, you ...