A 12-year-old boy was killed and 12 others injured in an accident during a performance by a circus at Chandina in Comilla on Friday night.The victim Hriday Shil, son of Ratan Shil, of the upazila, was an employee of a shop.According to source, a group of roving entertainers was performing at a trade fair being held on the Chandina Pilot High School ground around 9pm.Ariful Islam Arif, owner of ‘Car and motorcycle stunt exhibition group’ was performing stunts with a motorcycle inside a wooden well.Suddenly he lost his control over the bike and fell on the spectators who were watching the performance. Hriday died on the spot while others got injured.Chandina police officer-in-charge Rasul Ahmad Nizami said the accident caused a chaos among the spectators leaving 13 of them including Hriday, Arif and three women injured.