CALAIS, France — Migrants rushed the tunnel linking France and England repeatedly for a second night on Wednesday, and one man was crushed to death by a truck in the chaos, deepening tensions surrounding the thousands of people camped in this northern French port city. To get to the tunnel, migrants must cross a busy highway, scale or cut through barricades and fences, and pry open cargo doors or crouch in the freight cars that cradle the tractor-trailers.