DETROIT (AP) — About 13,000 U.S. auto workers have stopped making vehicles and headed for the picket lines.

Their leaders have been unable to bridge a giant gap between union demands in contract talks and what Detroit’s three automakers are willing to pay.

The United Auto Workers union went on strike against General Motors, Ford and Stellantis simultaneously for the first time in its 88-year history.

The limited strike at assembly plants in Michigan, Ohio and Missouri will likely chart the future of the union and of America’s homegrown auto industry.