A man on Monday killed his wife and two children before committing suicide by consuming poison in Uttar Pradesh's Kushinagar district, police said. The eldest daughter of the assailant is battling for life in hospital.The incident happened in Bawli Chowk area of Padrauna when Madhav Murari attacked his wife Suman Singh (42), eldest daughter Madhvi (11), sons Vikram (8) and Mannu (4) with knife.His wife and two sons died on the spot while his eldest daughter, who took refuge in a neighbour's house, was rushed to a nearby hospital where her condition is critical, an official told IANS.Murari also died after he consumed some poisonous substance.The neighbours of the deceased told the police that there had been a marital discord between the couple and a court case going on for the past three years.