Despite several weeks of warnings from health officials to follow “social distancing” measures and wear face coverings in public, Americans across the US crowded beaches and parties over Memorial Day weekend, among the first tests of a post-quarantine return to “normal” amid the coronavirus pandemic, as officials end “lock-down” measures to reopen their states.Video from a Volusia County Sheriff’s Office helicopter on Saturday captured dozens of people blocking traffic near Daytona Beach, Florida, where officials required visitors to wear masks but have resigned that the mandate is “not realistic” or enforceable in large crowds.