U.S. retail sales tumbled by a record 16.4% from March to April as business shutdowns caused by the coronavirus kept shoppers away, threatened stores across the country and weighed down a sinking economy. The Commerce Department’s report on retail purchases showed a sector that has collapsed so quickly that sales over the past 12 months are down a crippling 21.6%. The sharpest drops from March to April were at clothiers, electronics stores, furniture stores and restaurants. A long-standing migration of consumers toward online purchases is accelerating, with that segment posting an 8.4% monthly gain. Measured year over year, online sales surged 21.6%.