More than 50,000 Los Angeles County workers were on strike again Tuesday, closing libraries and disrupting administrative operations in the nation's most populous county and organizing a large march in downtown LA. The two-day walkout that began Monday followed failed negotiations with the county for a new contract after the last one expired in March, according to the Service Employees International Union Local 721. The union represents employees including public health professionals, social workers, parks and recreation staff, custodians, clerical workers and others serving a county of 10 million residents. It will be the first time all of its about...