A Walkerton man is hospitalized in Indianapolis following an accident involving a grenade launcher at a private shooting range in Marshall County yesterday. Kevin Patterson, 41, of Walkerton, was firing a starburst grenade round from an AR-15 platform rifle when it detonated in the launch tube under the rifle barrel, according to officials with the DNR. Conservation Officer Corporal Ashlee Jackson describes the round as similar to an aerial firework. Patterson was taken to Methodist Hospital in Indianapolis for treatment of injuries to his arm. Officers from the DNR, Marshall County Sheriff’s Department and Indiana State Police responded.