The United Auto Workers union is on strike against General Motors, Ford and Stellantis, the first time in its history that it has struck all three of the nation's unionized automakers at the same time.
"On Strike at the Big Three. Stand Up Strike," the UAW tweeted out shortly after midnight.
Just hours before the contract expiration, the union identified the plants it would be striking as three massive assembly plants.
They are GM's Wentzville Missouri, which has 3,600 UAW members on its staff; Ford's Michigan Truck plant in Warren, Michigan, which will have 3,300 strikes; and Stellantis' Toledo Assembly complex in Ohio, where 5,800 will be be on strike.
In a statement, GM said it was "disappointed" but would continue to bargain.
"The UAW has informed GM that they are on strike at Wentzville Assembly in Missouri as of 11:59 pm. We are disappointed by the UAW leadership's actions, despite the unprecedented economic package GM put on the table, including historic wage increases and manufacturing commitments," the statement read.
"We will continue to bargain in good faith with the union to reach an agreement as quickly as possible for the benefit of our team members, customers, suppliers and communities across the US," GM said.
This is a developing story. It will be updated.