On May 3, 2006, at 12:01 a.m., EST, Norfolk Southern Corporation (NS) train 72NC201 was traveling west on the Pittsburgh Division in route from Huff Power Plant at milepost PT 288.4 on No. 2 Main track with two locomotives, 59 loaded hopper cars, and two helper units. The recorded speed was 41 mph, when the train received an undesired emergency brake application. The investigation revealed the lead two locomotives and first thirty hopper cars loaded with typsum were derailed. The westbound train was crossing from 2 Main track over to 1 Main track when the lead axle (6), on NS 6600, hit the switch point and caused the train to derail. Both No. 1 and No. 2 Main tracks were effected by the derailment. At the time of the accident it was dark and overcast, with minimal wind about 4 mph. The temperature was 52F. The primary cause of the accident was determined to be caused by the companion alternator being wired incorrectly, on locomotive NS 6600, when installed at NS's Juniata Locomotive Shop. Locomotive had just received an overhaul and a 92-day periodic inspection at the Juniata Locomotive Shop. the crossed wires caused the control circuits to be by passed. When dynamic brakes were applied, it allowed the field current to exceed the allowable threshold of 960 amps and go as high as 1200 amps. This caused the locomotive to apply the dynamic brake fully even when in position 2. This caused the no. 6 and no. 4 axles on the lead truck on NS 6600 to develop large flat spots. The flat spots were large enough to cause the wheels to develop groves in the tread of the wheel. When the lead axle (no. 6) started through the crossover it hit the switch point lifting the locomotive causing it to derail. A contributing factor was that the crew did not follow NS procedure to stop and inspect the train when the second warning reported detector not working, per NS, Office of Superintendent, Pittsburgh Division, Operating Bulletin No. 2, effective January 1, 2006. The crew was not taken for Post Accident Toxicological Testing; because, NS's estimate of the damages was below the required threshold. The estimate for damages was $585, 184 for equipment and $145,000 in track, signal and communication damages (T&SC). Total damage to equipment and T&SC was $730,184. The No. 2 Main Track was restored for service on May 4, 2006, around 1:50 a.m. The No. 1 Main track was restored for service on May 4, 2006, around 3:40 a.m.