>> reporter: the cdc cutting the recommended quarantine time in half for all americans infected with covid-19, from ten to five days, if they're asymptomatic for five days. by 5:00 in the morning, lines of south florida were forming with prospects of free covid testing kits luring thousands. >> empty shelves everywhere. >> they're all in stock. they're all fine, but i guess they all disappeared in a matter of three days. like they just weren't there. >> reporter: at this library in miami-dade county, you're looking at two different lines right now. this is for free testing kits. this one is for testing on site. both of them snake around the building in both directions with no end in sight. it's a miami microcosm of a national crisis. chaos from new york to charlotte