An annual tradition limited to 500 climbers is underway with registration open for the annual Tri-Cities 9/11 Memorial Stair Climb at Bristol Motor Speedway.2021 will mark the 20th anniversary of 9/11, and event organizers are hoping for a record-setting turnout.The September 11 event will be the seventh Tri-Cities Memorial Stair Climb. In previous years, the event has raised $180,000 for the National Fallen Firefighters Foundation.Climbers will be given an ID tag of a first responder that lost their life on 9/11 as they climb up 110 flights of steps.For more information check out TriCitiesStairClimb@gmail.com.