KALLAMBALAM: A youth, who was seriously injured after his motorbike collided with a school bus, died while undergoing treatment. The deceased is Karthik (20), son of Madavoor native Babu and Ramya. The accident took place on Monday around 3.30 p.m. According to witnesses, the bike driven by Karthik hit a private school bus on the Puliyarkonam - Channarukonam road. He died on Friday evening while undergoing treatment. He has a sister: Krishna.