Pune: Six labourers were killed and at least two injured after the wall of an educational institute collapsed on their makeshift shelters in Ambegaon area here, officials said Tuesday. According to the fire brigade officials, the incident occurred on Monday night. “The wall of Singhad Institute collapsed on the makeshift shelters of labourers in which six people were killed and two-three others injured,” an official said. District Collector Naval Kishore Ram said prima facie it seemed that a tree fell on the college wall and then they collapsed on the shanties, which had been set up at an under-construction site. He said an investigation was underway to ascertain to whom the under-construction site belonged.