Houston officials say they are asking tough questions to figure out what caused a stampede at the Astroworld Festival that left eight victims, one as young as 14-years-old, dead. Houston Police Chief Troy Finner confirmed a security officer, who was administered Narcan, felt a prick in his neck before going unconscious and medical staff confirmed seeing what appeared to be an injection marking. Finner added they are now conducting a criminal investigation involving their homicide and narcotics divisions. Houston Mayor Sylvester Turner says while nothing is being left off the table, he urges people to not buy into online rumors and remain respectful to the victim's families while the investigation is being conducted.