Transport secretary, Sean Duffy, confirms the US has the ‘safest’ airspace in the world, following a deadly plane-helicopter crash in Washington DC. More than 300 first responders and rescue workers were deployed after a packed passenger jet collided with a US Army helicopter and plunged into the Potomac River - but no one is reported to have survived the crash. #washingtondc #transport #safe #flight #usa #crash #breakingnews