The Ford Motor Company's Rawsonville Plant in Michigan is being converted into a ventilator factory, as hospitals battling the coronavirus report shortages of the life-saving devices. Ford expects to start building the devices this month and ramping up to 7,200 a week.

The company has promised to deliver 50,000 by July 4, which may be too late for cities with an urgent need for ventilators right now.

Explaining why it will take weeks to start the work, Ford's Adrian Price told CBS News correspondent Kris Van Cleave, "There's quite a bit that goes into taking a design that is currently being produced at two-a-day and scaling that to make over 7,000 a week."

Price, who is running the project, said the company is used to building big automotive products. "Scaling to produce something like a small ventilator requires different sourcing and components and different capability," he said.

Ford also is making face shields at a rate of one every 10 seconds. It delivered hundreds to first responders in the Detroit area.

"That will save not only the lives of our firefighters and paramedics but the lives of the public," said Ed Cann, deputy chief and fire marshal at the Allen Park Fire Department.

The effort by Ford, as well as General Motors, is reminiscent of World War II, when Detroit built trucks, tanks, and even planes. The plant where Ford will assemble ventilators is just down the road from the airfield where it once built B-24s bombers.

"Supporting in times of crisis is kind of built into Ford's DNA," Price said.

This week, GM is validating its manufacturing process for ventilators. Production starts next week, and hundreds of employees will be back at work and need to be kept healthy.

"The biggest challenge, number one, is making employees feel comfortable coming back to work because right now they're in their homes, it's a safe environment, they can control it," said Dr. Jeffery Hess, GM's medical director.

Measures aimed at protecting the workers include temperature checks at the door, mandatory mask-wearing and work stations at least six feet apart. Work stations will be disinfected before and after each shift.

"We have to do this. This is vitally important to the American people and those who are sick," Hess said.

Starting next week, hundreds, if not thousands, of ventilators will be rolling off the line, first at GM, then at Ford, with a goal of about 17,000 a week by May.