An accident at Rosedale Industrial Park claimed the life of a 31-year-old city man Tuesday. Jonathan Magill of the 3500 block of Noble Street was pinned underneath the rear of a tractor trailer shortly after 2:30 p.m. The mechanic was working on the truck, with other employees at Eastern Truck and Trailer Corporation, when the trailer fell on him. Rescue crews arrived at 2:48 p.m. to the scene in the 7500 block of Lake Drive and extricated the victim from beneath the truck. He was in cardiac arrest, when he was taken to Johns Hopkins Bayview, where he was pronounced dead, fire officials said.