Officials with the local General Motors plant say a parts shortage is impacting their work force. According to the plants' automated information line, Work on Monday's third shift was cancelled. The first, second and third shifts were also called off Tuesday. Wednesday's first shift has also been cancelled. However, the phone line advised that skilled trades, material, final process and salaried workers are to report as scheduled. With the shortage, shifts are expected to work Friday night into Saturday. Workers are asked to call their information line. The number is 866-503-7755.