Detroit: More than 49,000 members of the United Auto Workers walked off General Motors factory floors or set up picket lines early Monday as contract talks with the company deteriorated into a strike.
Workers shut down 33 manufacturing plants in nine states across the U.S., as well as 22 parts distribution warehouses.
It wasn't clear how long the walkout would last, with the union saying GM has budged little in months of talks while GM said it made substantial offers including higher wages and factory investments.
It's the first national strike by the union since a two-day walkout in 2007 that had little impact on the company.
GM workers joined striking Aramark-employed janitors on the picket lines Sunday night at a sprawling factory on the border between Detroit and the small town of Hamtramck.
Worker Patty Thomas said she wasn't scheduled to picket, but came out to support her colleagues at the car plant, which GM wants to close. She's heard talk that GM may keep the factory open and start building electric pickup trucks there, but she's skeptical.
Striking GM employees were joined on the picket lines by workers from Ford and Fiat Chrysler, who are working under contract extensions.