It is the only USA source of those support beams, as well as other components used by some of Ford's competitors, including the cross auto beams that instrument panels in some Fiat Chrysler products are mounted on.
Fire at the Meridian Magnesium Products plant which supplies Ford with radiator support has led to shortage of vital parts for Ford F-150. The plant continued to produce Chevrolet Colorado and GMC Canyon mid-size pickups. It's not yet clear when F-150 production will return to normal levels.
Ford has not announced when production of the F-150 will start up again. The plant employs more than 400 workers and is the city's largest employer.
The F-150 is built only at the two sites, and there is no scheduled date for the reopening the Kansas City Plant.
But if the shutdown lasts a month, buyers may discover the version of the truck they want - the type of engine, or the type of cab configuration or trim - won't be available.
F-Series pickups generate most of Ford's profits, with Morgan Stanley recently assigning a higher valuation to the franchise than the entire company. The automaker's other source of the popular F-150, in Dearborn, Michigan, may go down this week, said a person familiar with the situation, who asked not to be identified discussing speculative matters.
"This is an extremely fluid situation", Kelli Felker, a Ford spokeswoman, said in an interview.
The fire also affected production of the Fiat Chrysler Automobiles plant in Windsor, Ontario, that produces the Chrysler Pacifica minivan. The company does not expect to lose sales due to shutdown and expect to make up the production over time. "FCA continues to work with the supplier's team on recovery efforts".
Michelle Krebs, analyst with industry analysis company Cox Automotive, said without information on how long Meridian will be down, it's hard to say what the impact of a production halt could be.