Traffic quickly slowed Thursday afternoon just before 5:30 on the stretch of Interstate 81 near mile marker 58. Cars were trying to avoid a tire casing that was in the roadway. The vehicles slowed and an unidentified motorcycle rider was unable to stop as quickly. The bike and rider skidded out of control. The Interstate was briefly shut down to investigate the fatal accident. No name is being released on the victim until family has been completely notified of the fatal accident.(CS)