As real-estate investment companies and other owners of large rental buildings default on their financing payments, renters have become the latest victims of the mortgage crisis. The Washington Post visits one such building in the Bronx where squatters have arrived to sell drugs and normal repairs have gone undone. This winter, according to the paper, such problems could spread throughout the country as foreclosures on large rental-unit buildings increase. One researcher said that 65 percent to 75 percent of multifamily buildings could face refinancing problems in the future. "We're at the front end of that wave," said an official at the U.S. Department of Housing and Urban Development. "Are we concerned? Absolutely."