The flight crew’s misidentification of the intended landing runway. Contributing to the incident were (1) the flight crew’s failure to perceive and correctly interpret visual and auditory indicators – including electronic guidance – that they were approaching the incorrect runway which was likely the result of a degradation in cognitive function brought on by working within their window of circadian low, increased workload, and fatigue, and (2) the air traffic controller’s failure to monitor the arriving flight after issuing a landing clearance.