During the third week of March 2020, with little public debate and less warning, Americans were told to stay in their homes indefinitely as COVID cases climbed. There were only a few days between bland reassurances and lockdown orders — just enough time to go panic shopping for toilet paper.

The first pandemic year represents a crisis distinct from the period after vaccines became widely available. Congress should establish something like the 9/11 Commission — independent and bipartisan — to reexamine why our early response was so disruptive and yet so ineffective. A report issued in time for next year’s anniversary of the start of the pandemic might identify weaknesses in the country’s general inability to deal with the next crisis, whatever that entails.

Some eye-opening analyses covering that first year have recently appeared in “Lessons From the COVID War,” by a panel of scientists and policy experts, and “The Big Fail: What the Pandemic Revealed About Who America Protects and Who It Leaves Behind,” by journalists Joe Nocera and Bethany McLean. But an official bipartisan treatment would have a big impact on our polarized nation.

Such a commission should first address why our elected leaders and expert agencies didn’t warn the public sooner. There was strong evidence by early February 2020 that this disease had already spread far beyond Wuhan, China, that it could travel invisibly through mild cases, and that the oldest people were at highest risk.

Some fair warning could have helped people take voluntary measures to avoid infection and prepare for disruption. But for much of January and February we got false reassurance. Even when Nancy Messonnier of the Centers for Disease Control and Prevention said on Feb. 25 that the virus might cause “severe” disruption, CDC deputy director Anne Schuchat pushed back, saying “our efforts at containment have worked.” It wasn’t until mid-March that the White House declared COVID a national emergency.

The delays in issuing clear warnings were part of a perverse disregard for the effects of time in a crisis. When protective measures began mattered. So did the timing of lifting or changing those measures. People can better stick with sacrifices that have a specific duration and a realistic goal.

Waiting to issue warnings and directives until after the disease was widespread meant more deaths — and the need for more extreme measures to get the same level of mitigation. And it isn’t hindsight bias to say that extreme measures such as shutting schools, businesses and public events would have been less harmful if done for two or three weeks rather than months.

The scenes of people dying in hospital corridors in Italy made it seem necessary to take drastic measures in the U.S. to “flatten the curve” of infection, but there was no scientific case for trying to eradicate an already widespread virus by keeping extreme measures in place long term.

A COVID commission could also look at what government, employers and communities might have done to prevent deaths among essential workers and their families. While Americans saw limited improvements in paid sick leave policy, the situation called for more. Essential workers who were at risk or lived with people in fragile health should have been able to opt out of work — their jobs taken over temporarily by the many healthy, younger Americans who were unafraid and whose mental health might have improved with the chance to contribute rather than stay cooped up alone.

And a special investigation could also help puncture the thin excuse that U.S. leaders made bad decisions because of a lack of data on a novel virus. Even in those early days of 2020, we had enough information to act more rationally. By early April, there was already growing evidence that the virus was spreading primarily indoors through airborne transmission and there was very little risk outdoors.

Blunt closures of businesses, schools, beaches and parks threw that knowledge out the window — and they didn’t represent scientific consensus. Michael Osterholm, director of the Center for Infectious Disease Research and Policy in Minnesota, cowrote a Washington Post op-ed published on March 21, 2020, warning that indefinite, sweeping lockdowns were not the best course of action for saving lives:

“The best alternative,” he wrote, “will probably entail letting those at low risk for serious disease continue to work, keep business and manufacturing operating, and ‘run’ society, while at the same time advising higher-risk individuals to protect themselves through physical distancing and ramping up our health care capacity as aggressively as possible.”

A targeted strategy could have harnessed what scientists had discerned about who was at the most risk of dying and which kinds of work were riskiest.

Osterholm stood by this view when I spoke to him this month. (And to give credit where it’s due, he was the first to get me thinking about a 9/11 Commission for COVID.) He reminded me that he favored short-duration measures to slow the rate of spread and keep hospitals from being overwhelmed. And he was concerned that long-term lockdowns would increase the death toll among “essential workers,” many of whom had health conditions that put them at elevated risk, or lived in crowded housing with elderly relatives. His worries came true.

Lockdowns caused homes to become more crowded — with college students moving in with families, school-age kids at home and others spending much more time in their houses or apartments. Public health researchers have confirmed that hours of household exposure caused many more cases than exposures of less than 30 minutes. Again, time matters.

A COVID commission should also measure the lasting impact of these early fumbles. After vaccines were introduced, the U.S. started to see many more deaths than other comparably wealthy countries. We had lower vaccine uptake in part because the public health community had lost the people’s trust during that first year.

The justification for blunt, long-term restrictions was the assumption that more people would die as a result of more targeted measures. But that needs close examination — it’s also possible that those policies made the situation here much worse and deadlier than it had to be.

Lots of countries made mistakes as COVID spread around the world. The only way to learn from them is to give them a hard, nonpartisan look.

F.D. Flam is a Bloomberg Opinion columnist covering science. She is host of the “Follow the Science” podcast.