Bhopal, June 6 -- Two workers were killed and seven others injured after a section of the roof collapsed inside the Bangwar underground coal mine of South Eastern Coal limited (SECL) in Madhya Pradesh's Shahdol district on Friday, police said. Dhanpura police station in-charge Khem Singh said the accident occurred in Sohagpur area near pillar no. 45, approximately two kilometers inside the main entrance of the coal mine. The deceased have been identified as Ballu Kol andGolu Baiga. The matter has been handed over to the Directorate General of Mines Safety for investigation, police said. "The accident took place on Friday afternoon during the construction of a stopping wall in the second shift. A section of the roof, comprising weak soil and rock, suddenly collapsed and trapped the workers beneath the debris. A safety barrier was being constructed in underground coal mines to control ventilation, prevent the spread of hazardous gases, and seal off abandoned or worked-out sections," Khem Singh said, adding that a probe is underway....