A broken air-conditioning belt caused smoke but no fire at Hammond High Magnet School shortly before lunchtime on Wednesday. Tangipahoa Parish School Superintendent Melissa Stilley said school officials contacted the Hammond Fire Department after they reported smoke on the second floor of the north wing. Emergency responders checked the school thoroughly and discovered the problem stemming from a broken belt in an air conditioning unit. Stilley said the district’s HVAC contractor was on site and would be able to complete the repair yesterday. Stilley said she expected classes will go on as scheduled this morning.