WASHINGTON — Devastated by the coronavirus pandemic, the U.S. economy is sinking. And the plunge is accelerating.

Now, as some businesses in a few states start to trickle back to work, hopes are beginning to arise that the economy, damaged as it is, might be poised to rebound by the second half of the year. If more employees and consumers were to gradually return to working and spending, the idea goes, the economy might be able to mount a sharp comeback.

Yet most economists have the same response: Keep such expectations in check.

Among their concerns is that the coronavirus could flare up again after the economy is re-opened, forcing businesses to shut down again. Another is that people — employees and consumers alike — will remain too wary of contracting the coronavirus to return to anything resembling normal economic behavior. If that were the case, no meaningful economic recovery would likely take hold.

The U.S. economy shrank at a 4.8 percent annual rate in the January-March quarter, the government estimated Wednesday, as the pandemic shut down much of the country.

Yet the drop in the first quarter will be only a precursor of a far grimmer report to come on the current April-June period, with business shutdowns and layoffs striking with devastating force. With much of the economy paralyzed, the Congressional Budget Office has estimated that economic activity will plunge this quarter at a 40 percent annual rate.