In Karnataka, four persons were killed and five injured when a five-storeyed under-construction building collapsed and fell on a hostel in Bellary. Police said that the mishap took place in Gandhinagar area of the city last night.<br/><br/>The dead included a 22-year-old student of the hostel.<br/><br/>An injured worker rescued from the debris told the police that at least 20 people were still trapped in the debris. Rescue operations are on.