MESA, Ariz. - (AP) - President Barack Obama says his $75 billion plan to tackle "a crisis unlike any we've ever known" in home foreclosures is necessary to help save the economy.

Obama unveiled the plan in Arizona, hard-hit by the housing crunch. More expensive than expected, it aims to keep 9 million people from losing their homes.

One part will ease refinancing for people who owe more on their mortgages than their homes are currently worth. Another provides incentives for mortgage lenders to help those on the verge of foreclosure.

Speaking at a high school outside Phoenix, Obama said the plan won't save every home but it will prevent "the worst consequences of this crisis from wreaking even greater havoc on the economy."