New Delhi, Oct. 8 -- A 24-year-old man, who allegedly stabbed his friend and a local, identified as Rajender Kumar (57), during a fight, was killed by Kumar's three sons in outer Delhi's Mangolpuri area, police said. The incident occurred late Monday night. The deceased, Rahul Singh, succumbed during treatment. Police said the altercation began between Singh and his friend, Ritik Himanshu (24) over a work-related issue. During the argument, Himanshu slapped Singh, who then left the scene, returned with a knife, and stabbed Himanshu in the thigh and back. Kumar intervened and got stabbed too. "Kumar's sons witnessed the fight and rushed to stop it. They overpowered Singh, snatched his knife and assaulted him with the same weapon and sticks,...