They realized their granddaughter Makayla had died exactly five years earlier. She had Krabbe disease—a rare neurodegenerative illness that strikes infants and usually kills them in less than four years. Makayla died at the age of two.

“We were very sure [the Powerball jackpot] was divine intervention,” Rosenau recalls, “and we were very sure what we were supposed to do with it.”

What they hadn’t counted on, though, was that human intervention can be destructive. What happened next is a heartbreaking tale that shows how powerfully fees and commissions can pervert financial advisers’ judgment and crush their clients’ wealth.