On April 1, scores of federal workers lined up outside of the Department of Health and Human Services HQ in Washington, DC – not knowing if they still had a job. But it was no April Fools' Day joke. Here's everything you need to know about the massive layoffs affecting 10,000 employees at the US health agency, which oversees the FDA, NIH, and CDC. Plus how President Trump's HHS Secretary Robert F. Kennedy Jr. has defended the overhaul in this explainer video from The Post.