The school year is underway at Castle Hills Elementary in the North East ISD, and masks are optional. Classes started Monday, the same day the American Academy of Pediatrics recommended all students keep wearing masks whether they've been vaccinated or not. District officials say they can't mandate masks because of Gov. Greg Abbott's executive order saying local requirements can't be stricter than state mandates. The school's principal says about 15 to 20-percent of the students are wearing masks.