LAS VEGAS -- WARNING: This video contains graphic content
The rapid-fire popping sounded like firecrackers at first, and 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.
In the chaos, terrified concertgoers searched for their loved ones, shielded each other from gunfire and scrambled to help others injured in the shooting.
Cellphone video was filmed by Hayward resident Ricky Rosas, who survived the shooting.
The Associated Press contributed to this report.
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LAS VEGAS MASS SHOOTING