A dilapidated building collapsed at Railpet here on Tuesday morning. In this tragic accident, a two-and-a-half year old boy along with his grandmother were killed. The mishap took place in the early hours of Tuesday. Station House Officer, Kothapet, D. Venkanna Chowdary said that the single storied building was constructed more than 100 years back. An auto driver Maganti Prasad was staying in the building with his family for some years.