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Houston Police Chief Troy Finner said Monday that he met with Travis Scott before his concert Friday to express concerns about public safety at the Astroworld Festival.

The chief said a criminal investigation continues into the events that led to the deaths of eight young people during a crowd surge at Scott's concert. The investigation includes a security guard who said he felt a prick in his neck before he passed out in the crowd. Finner confirmed that medical staff found what appeared to be a needle prick in his neck, KHOU reports.

Fans caught up in the chaos said people in the crowd of 50,000 started pushing toward the front as a timer clicked down to the start of performance.

Fans say they were begging Scott and his team to stop the concert when dozens of people passed out. Scott did stop, at one point, to ask for help for one unconscious fan but then continued performing for more than half an hour after the Houston Fire Department declared a mass casualty event.