"Wendy's home had appreciated in value by about $100,000, only months after she and her husband bought it. So, they took out a second mortgage for almost $80,000 to enhance their new home. It was at 8% interest. When the housing bubble burst, that $100,000 in equity evaporated. But, the interest on that second adjustable rate mortgage by now had climbed from 8% to almost 16%, creating a monster of a monthly payment they couldn't handle. 'Then, it just gets pulled from right out underneath you.' Wendy says her marriage even broke-up over this. Now the couple faces possible foreclosure on the house" (KVOA).Debtors often display this unfortunate tendency to turn even a $100k windfall into more debt, to eliminate increases in net worth, to eradicate any trace of even accidental equity.
Remember that the $100k was only a paper profit, not real wealth, because they did not sell the home at the high price (they ignored the basic, old "sell high" truism).
They ignored the chance to increase their income and instead increased their outgo (spending)--the opposite of basic financial advice to increase income and decrease outgo.