Today, FEMA is one of four major branches of DHS. About 2,500 full-time employees in the Emergency Preparedness and Response Directorate are supplemented by more than 5,000 stand-by disaster reservists.
When [link|http://en.wikipedia.org/wiki/Mount_Rainier|Mt. Ranier] blows, FEMA's not going to be able to do much with 2500 people. Their mission is to coordinate other levels of government and agencies in responding.
That said, FEMA did a terrible job at coordination. Whether it was because they were overwhelmed, or didn't follow the existing plans, or the plans were inadequate, or were simply incompetent (or all of the above), I can't say.
Cheers,
Scott.