More than 6.6 million Americans filed for unemployment benefits in the week ended March 28. That tops the previous all-time record of almost 3.3 million initial unemployment claims set just a week ago, according to the U.S. Department of Labor.

In a two-week period the country has lost 10 million jobs—wiping out the past four years’ worth of U.S. job gains in a period as long as one paycheck.

But the real number of Americans who lost their jobs over the past two weeks is likely much greater than 10 million. Experts say that states are overwhelmed with the number of jobless claims flooding in, and they’re unable to process all the claims, meaning the real total may be even higher.

“In some cases the [state unemployment] websites don’t have a lot of feasibility for handling this…some people who lost their jobs last week still haven’t gotten through. We’re going to continue to see a backlog growing in the system,” says Peter Earle, an economist at think tank American Institute for Economic Research (AIER).

Across the nation unemployment sites are crashing from the influx of traffic, including Michigan’s, which went down for a bit on Tuesday.

Dan White, head of fiscal policy research at Moody’s Analytics, notes that one state he works with said it was receiving about 1.5 million calls per business day, and can only field 11,000 to 12,000 calls. He declined to name the state, but said more unemployment offices this week are turning to the private sector for help.

Pennsylvania is second in the nation with 783,331 initial jobless claims over the past two weeks. That’s more than much bigger states like Texas (431,023 claims), and New York (446,402 claims). The Keystone State leads those states because it has a simple and functioning unemployment site that can handle the volume better, White says. That gap between Pennsylvania and states like New York indicates that there are likely millions of claims in the U.S. that have yet to be processed, he adds.

“Four years of job gains wiped out in 15 days…Unemployment systems are just unable to deal with it,” Earle says.

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