General Motors announced today that it will be closing several plants in the US and Canada, including the Janesville, WI plant, one of GM's oldest. This came as a surprise to its employees. The plant closures have been the product of very poor SUV and pick up sales. GM is also seriously thinking of phasing out its Hummer line as automakers are making the switch to manufacturing fuel-efficient cars. Parts suppliers will also be affected by the plant closures.