BILLINGS, Mont. — Fuel-hauling tank cars need retrofits to prevent more explosive train wrecks — and the public can’t wait another decade for the improvements as has been suggested by the industry, U.S. safety officials said. The National Transportation Safety Board issued a series of recommendations Monday after a spate of fiery accidents revealed shortcomings in voluntary industry standards for cars hauling oil, ethanol and other flammable liquids. The NTSB said the cars should be replaced or …