 For NPR News in the Twin Cities, I'm Kelly Blyer. Unionized Minneapolis park workers are on day two of a week-long strike that began on the 4th of July. The park board says those who walked off can't return to their jobs until an agreement is ratified. The union represents more than 300 workers and says the board's final contract fails to adequately raise wages or address safety concerns, for example, having to pick up needles from parks.