"Freedom Convoy" protests are still paralysing the Canadian capital Ottawa. The truckers are also blocking the busiest international crossing in North America. The Ambassador Bridge between Detroit, Michigan and Windsor, Ontario carries a fourth of all trade between Canada and the US. Canadian lawmakers are becoming increasingly worried about the economic effects of the protests against vaccine mandates and other Covid-19 restrictions. Our correspondents François Rihouay, Joanne Profeta and Gloria Henriquez report.