NEW YORK — When Domenico Colombo saw that his monthly mortgage payment was about to balloon by 30 percent, he had a clear picture of how bad it could get. His payment was scheduled to surge by an extra $1,500 in December. With his daughter headed to college next fall and tuition to be paid, he feared ending up like so many neighbors in Ft. Lauderdale, Fla., who defaulted on their mortgages and whose homes are now in foreclosure and sporting ‘For Sale’ signs. Colombo did manage to renegotiate a new fixed interest rate loan with his bank, and now believes he’ll be OK — but the future is less certain for the rest of us. In the months ahead, millions of other adjustable-rate mortgages like Colombo’s will reset, giving them a higher interest rate as required by the loan agreements and leaving many homeowners unable to make their payments. Soaring mortgage default rates this year already have shaken major financial institutions and the fallout from more of them, some experts say, could spread from those already battered banks into the general economy. The worst-case scenario is anyone’s guess, but some believe it could become […]