Dr Martens profits tumble amid US supply problems

British bootmaker says it faces ‘challenging’ US market and rising costs at LA warehouseDr Martens said it has struggled to sell its chunky lace-up boots in the US and admitted attempts to correct “mistakes” in its American supply chain had triggered a slide in its annual profits.The British bootmaker said it had faced falling demand in the US, blaming what it called a “challenging consumer environment”, as shoppers reined in their spending in the face of high