A man was stabbed repeatedly while walking in Chinatown this week in what appears to be a random attack, Los Angeles police said. William Yu, 46, was walking near the intersection of Alpine Street and Broadway on Wednesday afternoon when he was approached by the assailant, police said. Yu was stabbed in the head and neck, along with lacerations to his groin and stomach, they said. Yu’s brother David Yu wrote in a social media post about the attack: “As people called police, nobody helped to intervene. … My brother was in the fight for his life.” Timothy Mears, 50, was arrested at the scene. According to jail records, his bail was set at $100,000.