GM's Lordstown Assembly in Ohio, Detroit-Hamtanck Assembly in Michigan, and Oshawa Assembly in Ontario are all at risk, as GM has announced that it will not allocate new products to them.

All of the products currently being assembled at the plants are expected to stop by 2019, leaving the plants with nothing to produce and putting them at risk of being closed.

"This callous decision by GM to reduce or cease operations in American plants, while opening or increasing production in Mexico and China plants for sales to American consumers, is, in its implementation, profoundly damaging to our American workforce," said Terry Dittes, UAW Vice President, Director GM Department. "GM's production decisions, in light of employee concessions during the economic downturn and a taxpayer bailout from bankruptcy, puts profits before the working families of this country whose personal sacrifices stood with GM during those dark days. These decisions are a slap in the face to the memory and recall of that historical American made bailout."

The company hasn't technically announced that the plants will be closed, though GM said that the actions it announced today will save it $6 billion by 2020. The actions do come at an expected cost of up to $3.8 billion in accelerated asset write-down and pension charges.

The decision puts 6,300 jobs at risk. Without products to produce, what its 3,300 American and 3,000 Canadian employees will do is a bit of a mystery. Unifor, the union that represents Canada's Oshawa plant, is still calling for allocations, though. 

"Unifor does not accept the closure of the plant as a foregone conclusion," Jerry Dias, Canada's Unifor union president, said in a statement. "Oshawa has been in this situation before with no product on the horizon and we were able to successfully make the case for continued operations. We will vigorously fight again to maintain these good-paying auto jobs."

GM is heading into negotiations with the UAW in 2019 (and Canada's Unifor in 2020). The negotiations will, presumably, be tense, since GM, along with this announcement, also said that it would be cutting 15% of its North American workforce (8,100 jobs) by the end of next year and would slash its volume of global executives by 25%.

Two unidentified plants outside of North America will also be closed, says GM.

"The actions we are taking today continue our transformation to be highly agile, resilient and profitable, while giving us the flexibility to invest in the future," said GM Chairman and CEO Mary Barra. "We recognize the need to stay in front of changing market conditions and customer preferences to position our company for long-term success."

The cuts follow GM's recently publicized decision to offer buyouts to 18,000 of its employees. The company has also been exiting (Europe) or restructuring (South Korea) unprofitable markets.

Lordstown currently builds the Cruze, while Detroit-Hamtramck builds the Volt, the Impala, the Buick LaCrosse, and the Cadillac CT6. Oshawa, meanwhile, builds the outgoing pickups, as well as the Impala and the XTS.