(Portland, OR) -- The Multnomah County Sheriff's Office is releasing the name of a teenager who was killed by a falling tree limb during a tree planting event on Saturday. Police say 14-year-old Christopher Kelly was helping to plant trees in the area of Thousand Acres Dog Park at the Sandy River Delta in Troutdale. He was working about a quarter-mile from the main road when the accident happened. Kelly was a student at Central Catholic High School.