Special education students seem to be disappearing in Texas. The Lone Star State diagnosed just 8.8 percent of its public school students as having special needs in 2011, down from 12 percent in 2000. Texas now has the lowest percentage of special education students in the nation - a full 4 percentage points below the U.S. average. Urban giants like the Houston and Dallas school districts identify even fewer children at 7.9 percent and 7.7 percent, respectively. While some educators take the declines as a positive sign, advocates fear the state might be under-diagnosing to reduce costs or to circumvent accountability measures. Others worry that the growing immigrant population may be underserved by a system that’s difficult for even the most knowledgeable parents to navigate.