PHILADELPHIA (WPVI) -- Police are looking for a suspect accused of knocking a man unconscious in Philadelphia's Fishtown section.It happened on March 31 right after 2 a.m. at the intersection of Frankford and Girard Avenues.Police say the victim got in an argument with three other men. During the dispute, one of them punched the victim in the face, causing him to fall backward and hit his head.The 24-year-old was transported to the hospital where he was treated for a broken nose, a concussion and a head laceration.If you know anything about the incident, call police at 215-686-TIPS.