Several reports were received that an unknown race male was walking southbound on the aerial track near milepost 22.1. Officers responded to check the area, and trains performed track inspections, but the man was not located. At about 0755 hours, a man walked into John Muir Hospital in Concord and reported that he was suicidal, and had been on the BART tracks earlier. Officers responded and concluded that the man was in need of psychiatric evaluation. The man was transported by ambulance to County Hospital.