A Chinese state news agency says that 11 girls have died of carbon monoxide poisoning at a school in northern China's Shaanxi province after trying to make a fire to heat their room. The local news agency said Tuesday the 11 students at a secondary school in Yulin city died Monday after lighting the fire to keep warm. The report also did not give the ages of the girls or other details. It said the provincial vice governor had arrived to help investigate the case.