CNBC reports that April's jobs report will be horrific, and with the worst job losses ever, it should provide a critical look into the depths of the crater the economy has fallen into.

Economists expect a record 21.5 million jobs were lost last month, sending the unemployment rate sharply higher to 16% from just 4.4%, according to Dow Jones. But economists concede that unemployment rate could be as low as 11% or higher than 20%, because of the way the government collects the data in its survey.

At 16%, it would be the highest rate of unemployment since 1939, the tail end of the Great Depression and just before World War II.

"This is the biggest and most acute shock that we've seen in post-war history. It's a dramatic loss of output in a very short period of time," said Michelle Meyer, head of U.S. economics at Bank of America. When states began to shut down in March, among the first casualties were jobs in the restaurant and leisure industries, retailers, and at airlines.

Economists say the job losses in Friday's report could mirror what was in ADP's April payroll report, released Wednesday.

The government data should reveal the breadth of the job losses and detail the demographics of those who are now out of work, even if it is just temporarily.

"It's understood leisure and hospitality and retail have seen a large displacement of workers, and that's apparent in the claims numbers. The extent that has spread across the economy will tell us a lot, and the more it has spread, the more challenging it will be to return to normal," said Meyer.

"I think it will be concentrated in those industries, but I think it will be fairly broad-based. It's hard to escape this recession," she said.