Just when it looked like the housing market might be treading water, more American homes slipped underwater at the end of 2010, reports the AP. Now 23.1% of all mortgages, or 11.1 million, outweigh the value of the house they secure—up from 22.5% in the previous quarter. The number of underwater mortgages had fallen in each of the previous three quarters, though the AP cheerily notes that was because many had gone into foreclosure.
Another 2.4 million mortgages are nearing the tipping point, and prices will likely continue to fall in many markets, pushing them under. Nevada continues to be particularly hard-hit, with some two-thirds of homes underwater; Arizona, California, Florida, and Michigan all have about half. In a healthy market, typically 5% are underwater. (Read more underwater stories.)