The government's disaster relief chief says Hurricane Gustav is growing into a monster Category 5 storm. The storm that hit Cuba Saturday could reach landfall along the US Gulf Coast as early as Monday afternoon. Federal Emergency Management Agency chief David Paulison told reporters several times at a briefing Saturday that the storm was strengthening into a Category 5 hurricane. Gustav was a highly dangerous Category 4 storm Saturday afternoon. A Category 5 storm has winds greater than 250 kph. After Paulison's briefing, hurricane forecasters said the storm still was classified as Category 4 although it was intensifying rapidly. They are predicting it will grow into a Category 5 hurricane by early Sunday.