Updated from 1:15 p.m. ESTBy Mark Smith and Alan Zibel MESA, Ariz. -- Seeking to tackle "a crisis unlike any we've ever known," President Barack Obama unveiled an ambitious $75 billion plan Wednesday to keep as many as 9 million Americans from losing their homes to foreclosure. Announcing the plan in Arizona -- a state especially hard hit by the housing crunch -- Obama said that turning around the battered economy requires stemming the continuing tide of foreclosures. The housing crisis that began last year set many other factors in motion and helped lead to the current, widening recession. "In the end, all of us are paying a price for this home mortgage crisis," Obama said at a high school outside Phoenix. "And all of us will pay an even steeper price if we allow this crisis to deepen." But while talking in broad strokes about the importance of the issue to the economy as a whole, the president took care not to miss the pain that the housing problems are causing in individual families "The American Dream is being tested by a home mortgage crisis that not only threatens the stability of our economy but also the stability of families and neighborhoods," he said. "While this crisis is vast, it begins just one house and one family at a time." More expensive than expected, Obama's plan aims to keep between 7 million and 9 million people from foreclosure. Of the nearly 52 million U.S. homeowners with a mortgage, about 13.8 million, or nearly 27%, owe more on their mortgage than their house is now worth, according to Moody's Economy.com.