As the St. Bernard Parish (La.) district prepares to welcome about 4,000 students Wednesday for the start of another school year, its top administrator hopes to shift the focus away from Hurricane Katrina and the ongoing recovery. Two years after Katrina, the population of the parish remains at about half of the 67,000 who lived there before the storm. Still, three renovated schools will fully come on line this year to accommodate growing enrollment, which has risen from 334 in the weeks right after the hurricane to an anticipated 4,000 this fall.