A 24-year-old man was fatally stabbed in a troubled Manhattan park and a teen was slashed in Times Square on Thursday night, according to cops and sources. Two men got into a fight with four other men in Sara D. Roosevelt Park near Broome and Delancy Sts. just after 8:30 p.m., police and sources said. The attackers and victims were all believed to be homeless. A member of the larger group .