General Motors, Ford and Fiat Chrysler have agreed to close all of their North American factories through at least March 30 to allow the companies to thoroughly clean and sanitize their plants, after which plans to reopen will be evaluated "week-to-week."

The big picture: The decision will affect 150,000 hourly Big Three workers — with repercussions throughout their extensive supply chains. Honda earlier Wednesday announced similar action at its U.S. plants, which will affect 27,600 workers.

Tesla, meanwhile, was telling its employees to come to work at its Fremont, Calif., factory, despite a "shelter-in-place" order from Alameda County.

Between the lines: The extraordinary decision to halt operations came after intense pressure from union leaders.

Workers at a handful of plants were diagnosed with the coronavirus, prompting fear among employees that they would be infected.

The companies will work with union leaders on how to restart plants, along with health and safety procedures aimed at helping keep the workforce safe.

What they're saying:

GM Chairman and CEO Mary Barra: “We have been taking extraordinary precautions around the world to keep our plant environments safe and recent developments in North America make it clear this is the right thing to do now."

“We have been taking extraordinary precautions around the world to keep our plant environments safe and recent developments in North America make it clear this is the right thing to do now." UAW President Rory Gamble: "This will give us time to review best practices and to prevent the spread of this disease."

"This will give us time to review best practices and to prevent the spread of this disease." Kumar Galhotra, Ford’s president of North America: “Especially in these challenging times, we must continue working together and putting people first."

“Especially in these challenging times, we must continue working together and putting people first." Honda said it will continue to pay workers their full wages during the stoppage.

said it will continue to pay workers their full wages during the stoppage. Hyundai shut down production Wednesday night at its Montgomery, Alabama, plant Wednesday, after a worker tested positive for the novel coronavirus.

shut down production Wednesday night at its Montgomery, Alabama, plant Wednesday, after a worker tested positive for the novel coronavirus. Nissan is shutting down all three of its U.S. factories — in Smyrna and Decherd, Tennessee, and Canton, Mississippi, — for two weeks, starting Friday, per Automotive News.

is shutting down all three of its U.S. factories — in Smyrna and Decherd, Tennessee, and Canton, Mississippi, — for two weeks, starting Friday, per Automotive News. Toyota said it would suspend production at "all plants Monday and Tuesday next week for a deep cleaning to help contain the virus," Automotive News notes.

Editor's note: This article has been updated with new details throughout.