Kathmandu, October 23 A labourer was killed while another labourer and a passerby were injured when part of the third floor of an old building that was being demolished collapsed onto a road at a busy market place in Chabahil, this evening. The deceased has been identified as Deepak Tamang. He was engaged in demolishing the building. Ram Bahadur Kunwar, a passerby who was injured when the building collapsed near KL Tower, was rushed to nearby Dhirghayu Guru Hospital in Mitrapark. Jeevan Magar, another  labourer who was working at the site, escaped with minor injuries. Kunwar, who works at a nearby eatery was walking on the footpath when the building collapsed. Police have summoned contractor Buddha Lama and Govinda Shrestha, who had bought the house two months ago. They were told to bear treatment expenses of the injured. Deputy Superintendent of Police Pradeep Singh of Metropolitan Police Circle, Gaushala, said police were investigating the case and would arrest Lama and Shrestha if families of the deceased and those injured filed a written complaint against them. Apparently labourers were demolishing the building without wearing helmets or adopting other safety measures.