As COVID-19 spreads rapidly throughout the United States, it has begun to enter our prisons and jails, which confine more than 2 million people. We are on the verge of catastrophe—for incarcerated persons, staff, and their families, obviously, but also for the general public. Some officials have been sounding the alarm, and we’re beginning to see some action—but not nearly enough, and not fast enough.

Prisons and jails house hundreds of thousands of medically vulnerable patients—people at grave risk from COVID-19. But “social distancing” is all but impossible in jails and prisons. Space is limited; prisoners are double- or triple-celled, or housed in barracks-style dorms. They eat together; they share bathrooms; they are escorted from place to place by staff in close proximity. (Here and here are pictures used in support of a lawsuit seeking prisoner releases in California, illustrating this point.) Hand sanitizer is typically banned (because of alcohol content) and even soap is often scarce or too expensive for inmates whose jobs behind bars may pay only pennies a day. Copays often discourage medical care. Once a highly transmissible disease like COVID-19 makes its way into a jail or prison, containment will be extraordinarily difficult.

There will be two dire results. First, prison and jail medical capacity will quickly be overwhelmed. Then, incarcerated people with serious respiratory impairments will flood already underequipped community hospitals, particularly in rural areas where many prisons are located.

Second, once prisons and jails have incubated COVID-19, the disease will spread past the prison gates. While many institutions have already barred visitors in response to the pandemic, hundreds of thousands of staff members come in and out daily. And especially in jails—which hold shorter-term detainees, including those not yet tried for any crime—people are constantly being admitted and released, often after just a few days.

So prisons and jails are among the most dangerous pandemic sites—dangerous for prisoners, for staff, and for everyone outside. The virus might have a single initial entry point to an institution, such as an infected staff member. But after it spreads through the population there, it will have countless exit points.

Per capita, the incarcerated population in the United States is several times larger than that of nearly every other country in the world. That renders us uniquely vulnerable to this disease vector. It is nearly inevitable that this virus will hit our prisons and jails hard and soon. Indeed, it’s surely already in more of them than we know. The only question is how bad the damage will be. We can mitigate it only with swift and aggressive action.

The only way to really limit this catastrophe is by quickly reducing the number of people incarcerated. If we can get everyone out who doesn’t have to be there, it will also produce some critical space that institutions will need to enable social distancing and to isolate the sick, and might even make it possible to operate with reduced staff. And although some are already infected, there will be a smaller number if we act today than there will be if we act tomorrow, or next month. Moreover, we can minimize the risk those already infected pose to the community by ordering that those released stay at home for two weeks or more.

Governors of many states have the authority, under emergency powers and/or their ordinary clemency powers, to order quite sweeping steps. Courts can implement others (here’s a catalog of state Supreme Court orders so far, and also of litigation seeking emergency prisoner releases), and local prosecutors can be crucial actors as well. There are several key steps that states (and the federal system) should take:

1. Delay new sentences, except as absolutely necessary. Sentence start dates, sentencing hearings, plea hearings, and trial dates can be deferred until after the emergency. This will also help to protect court personnel and citizens called to jury service. A number of states—for example, Washington and Wyoming—have delayed criminal proceedings. (Obviously this only helps if it’s coupled with releases of the defendants.)

2. Sharply limit pretrial detention. Many people in our jails have not been convicted of crimes at all. Most are detained pretrial not because they pose a danger but because they don’t have money for bail. This is a serious problem at any time, but now, it endangers all of us.

Nobody should be detained pretrial unless there is clear and convincing evidence that they pose a flight risk or a danger to the public that cannot be satisfied with less restrictive means like home confinement. Prosecutors should not request money bail, and courts should not require it. Those already detained without a finding of unmitigable dangerousness or flight risk should be released and ordered to stay home instead. Again, a number of jurisdictions have taken at least significant steps in this direction. (They include Washington, California, South Carolina, and Harris County, Texas.)

3. Commute all sentences due to end within a year. Inevitably, hundreds of thousands of people will be released from prisons and jails during this emergency because they are due to be released. Keeping them behind bars until the crisis ends is not an option. Everyone will be safer if they are released now. The mechanism will vary by state—in some, governors can use their emergency or normal clemency powers. For the federal government, Attorney General William Barr took a baby step in this direction on Thursday, announcing plans to shift some older federal prisoners to home confinement. In some states, courts could order this approach. (California’s Supreme Court, for example, has ordered identification/release of those with two months or less left to serve, which is a good step, but the crisis is not likely to be over in just two months.)

The public safety risk would be minimal, and far outweighed by the benefits of reducing coronavirus spread. Many of those due for release within a year were convicted of misdemeanors or minor felonies and had short sentences to begin with. Others are people who have already served most of a longer sentence. Some have even already been granted parole but are awaiting various administrative steps for release. But all are due to be released soon anyway—the question is whether they bring the coronavirus with them.

Sentences could be commuted to time served or to house arrest for up to the remainder of the term. The order could even provide for releasees to return to prison if the state of emergency ends before their terms do. Domestic violence offenders could serve house arrest in a home other than that of their victim. Individuals released will need speedy reentry planning to support housing, health insurance enrollment, and medical care access as they get out. (This kind of reentry assistance is part of a recent release order in New Jersey.)

4. Release older and chronically ill individuals. Many older people behind bars are serving long sentences for long-ago violent crimes and are left out of steps targeting minor offenders. But even if past crimes were significant, nobody deserves the death sentence that COVID-19 could very likely become.

Moreover, the vast majority pose no risk to the public now (except as virus vectors). In a forthcoming study co-authored with J.J. Prescott and Benjamin Pyle, one of us assessed the crime risk posed by people with violent-crime convictions. We found that older individuals pose vanishingly small risks. For example, among homicide offenders released after age 55, only 0.4 percent were reconvicted of any new crime within the following three years. And those were ordinary releases. Replacing incarceration with detention at home (or in medical facilities) would presumably pose even less crime risk.

Some of the steps proposed here might seem radical in ordinary times. But these are extraordinary times. Throughout the country, governors and other public officials are taking sweeping, dramatic actions to protect the public from COVID-19. Ordinary Americans are upending our lives in ways we could not have imagined just a week or two ago. If we don’t think at the same scale about the brewing crisis in prisons and jails, we will all suffer the consequences.