 Ruben Rosario, a longtime columnist and reporter at the St. Paul Pioneer Press, died yesterday of complications tied to multiple myeloma, the newspaper said. He was 70 years old. Originally from the Bronx, New York, Rosario moved to Minnesota in 1991. He spent nearly 30 years working at the Pioneer Press, penning more than 2,000 columns. In his final column as a full-time employee, Rosario wrote that he focused on highlighting unheralded ordinary people and issues that deserved more attention.