TREBES, France – A gun-wielding extremist went on a rampage Friday in a quiet corner of southern France, killing three people as he hijacked a car, opened fire on police and took hostages in a supermarket, where panicked shoppers hid in a meat locker or ran through the aisles. After an hours-long standoff, the 25-year-old attacker was slain as elite police forces stormed the market.