A state of emergency was declared in the U.S. city of Miami Beach on Sunday over concerns that large crowds gathering for spring break would pose a coronavirus risk. Miami Beach officials extended an 8 p.m. curfew and emergency powers for up to three weeks to help control unruly and mostly maskless crowds that have converged on the party destination during spring break.Thousands of people have packed the city's Art Deco Cultural District, causing bedlam and lawlessness in recent days. University students typically celebrate spring break, leading some businesses to close voluntarily out of concern for public safety.