A natural gas leak forced the relocation of students from Confederation Secondary School in the Greater Sudbury community of Val Caron to another nearby school Monday morning. The Rainbow District School Board confirmed with CTV News that staff greeted students as they arrived and they were then relocated to nearby École Jean-Paul II while the source of the gas odour was determined. The gas was turned off and contractors were called in. Greater Sudbury Fire Services were also on site, conducting air quality testing. Students returned to the school shortly after 10 a.m. after fire services had deemed it safe. The city confirmed that Enbridge determined the leak was caused by a ruptured gas line on the roof due to ice buildup. Officials said the rooftop gas units have been turned off and the school is being heated by boilers during the repairs.