BANGALORE, March 16: Three persons were killed and over 31 sustained injuries when a building which was under construction, collapsed on Monday morning at the Indian Institute of Science (IISc) campus.The dead are identified as Rame Gowda (45), Joshi (45) both PWD Engineers and Karuna (35) a videographer. The injured, mostly workers, who sustained injuries on their heads and sustained fractures, were treated in the IISc campus hospital.The building under construction was meant for mounting a stand-by generator to the IISc campus. The roof work was being carried out, when half of the building along with scaffolding caved in. Joshi, Rame Gowda and Karuna were buried under the debris which weighed around 20 tonnes.According to sources, N Giriraj, a contractor had taken up the work of the building. The two PWD engineers were on deputation to the construction site.A videographer was hired on Monday to shoot the moulding work as they were using a new Japanese technology.According to the constructionworkers, they were watching from outside, how the new technology was being carried out. Mixed concrete were bought in vehicles and were being poured on the scaffolds, which was constructed for moulding. Soon, the whole roof, along with scaffolds came down.Some construction workers, who were on the top of the building, levelling the concrete mixture fell over the debris and sustained injuries. However, two engineers and the videographer, who were watching from below were buried under the debris. Three more construction workers are suspected to have been trapped under the debris.