Surprise inspections at 31 Dallas public high schools revealed eight were locked exit doors, a serious fire code violation. The citations follow an incident at Samuell High School last week, when students evacuating a fire with exit doors locked with chains. The Schools' Superintendent issued a directive to administrators to "clamp down" on principals to comply with fire codes. The schools cited include some of the most troubled, chronically failing high schools under state standards facing closure by the state unless they improve this year. Fire officials do annual inspections and respond to complaints about code violations, but the inspections are usually scheduled because of the volume of schools involved. School officials then may remove chains on doors.