Worst Mass Shooting in American History: At least 59 killed, over 500 injured as gunman opens fire at Las Vegas concert

By SALLY HO and REGINA GARCIA CANO, Associated Press LAS VEGAS (AP) — The rapid-fire popping sounded like firecrackers at first, so many in the crowd of 22,000 country music fans didn’t understand what was happening when the band stopped playing and singer Jason Aldean bolted off the stage. “That’s gunshots,” a man could be heard …