A barrage of gunfire erupted in downtown Kansas City, Missouri, near an outdoor celebration of the NFL champion Chiefs' Super Bowl victory, killing at least one person and wounding 21 others as throngs of fans scurried for safety. Police Chief Stacey Graves told a news conference three people were detained "and under investigation" in connection with the bloodshed near the city's landmark Union Station after a confetti-strewn parade. Graves said investigators had no known motive for the gun violence. Eleven of those hurt by gunfire or the ensuing chaos were children as young as 6. At least 22 people were…