The recession caused by the coronavirus has in a mere few weeks put millions of Americans out of work and under severe financial strain, including keeping a roof over their head.

Exhibit A: As of April 5, some 31% of the U.S. households that rent hadn't paid it for the month, the National Multifamily Housing Council said in a report Wednesday that tracks how the pandemic is affecting the housing market.

"The COVID-19 outbreak has resulted in significant health and financial challenges for apartment residents and multifamily owners, operators and employees in communities across the country," NMHC President Doug Bibby said in a statement.

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Although 69% of renting households were able to pay the April rent, that was down from 81% the prior month, according to the group, whose data cover 40 million renters. Renters in Louisiana and New York saw the biggest increase of unpaid April rent.

Those financial struggles come as millions of workers around the country are being laid off, with most of the country shuttering all but essential businesses in an effort to contain the virus that causes COVID-19. Economists expect the nation's unemployment rate to shoot up this month into double-digits.

Concerns about people keeping a roof over their head has led some states, including Arizona, California and Massachusetts, to temporarily suspend evictions.

Bibby said in a conference call Wednesday that most landlords still expect the majority of tenants to keep paying rent. But many property owners are working with residents who are struggling, offering them payment options such as letting people pay by installment or letting renters use their security deposits as payment. Other landlords are waiving late fees or credit card transaction fees.

Bibby said he expects more residents will have paid April rent in the next two weeks.

"Housing providers have financial obligations they must meet on a regular basis, including mortgages, utilities, payroll, insurance and taxes," he said. "And if renters are unable to pay their rent, rental property owners will not have the resources to satisfy their own financial obligations or run their communities in a safe and sanitary way."

Along with running into financial difficulty, other factors likely deterred people from paying the rent this month. Renters who mail their payment or use a dropbox could have been hesitant to venture outside, according to rent processing companies. Many landlords also have temporarily closed their offices, making it hard for residents who don't pay electronically to deliver payment.

"Checks have to get dropped off, checks have to get picked up — there's a human element to this process," said Brian Zrimsek of MRI Software, a maker of lease management tools, in the conference call. "People simply can't turn on electronic payments if they didn't already have it."