Almost one out of every two mortgage holders is likely to be underwater before the housing recession ends, according to a report by Deutsche Bank. That is, they will owe more than their properties are worth. As of March 31, it was roughly one out of four mortgage holders. This is one reason there's growing concern about a double-dip recession - if home values keep trending down, there will likely be new foreclosures. From Bloomberg:

Seven markets in states with the fastest appreciation during the five-year housing boom -- including Fort Lauderdale and Miami, Florida; Merced and Modesto, California; and Las Vegas -- may find 90 percent of borrowers underwater, according to the report.

No specifics on L.A., but in general it's better off than the above cities.