Travis Scott’s Astroworld: Criminal probe opened into stampede at Houston concert that killed 8

A stampede of fans surging toward the stage during rap star Travis Scott's Astroworld music festival in Houston killed at least eight people and injured dozens more as panic rippled through the crowd of largely young concertgoers, officials said on Saturday.

City Police Chief Troy Finner said his department has opened a criminal investigation by homicide detectives.

The disaster unfolded at NRG Park at around 9:30pm on Friday during the headline performance by Scott, a Grammy-nominated singer and producer, following what police and members of the crowd described as an escalation of unruly behavior throughout the day.

As fans in the sold-out audience of about 50,000 pressed toward the stage, people began to fall unconscious, some apparently suffering cardiac arrest or other medical issues, officials told reporters outside the venue. Minutes later the chaos was declared a "mass casualty incident."

"It happened all at once. It seemed like it just happened ... over the course of just a few minutes," said Houston Police Executive Assistant Chief Larry Satterwhite, who was at the front of the event when the situation began.

Satterwhite said he immediately met with promoters and they agreed to halt the show. Officials said the concert was brought to an end by 10:10pm.

An incident earlier in the day in which fans started "rushing" the festival gates was brought under control relatively quickly, said Finner, the police chief, adding it appeared unrelated to the deadly stampede.

Finner said police had 528 officers assigned to the festival on Friday, along with 755 private security personnel.

Throughout the day, 25 arrests were made - one each for marijuana possession and public intoxication and the rest for trespassing, Finner said.

The venue could have held up to 200,000, but organizers limited the crowd to 50,000, based on ticket sales, Peña said.

The investigation is likely to focus on security and safety protocols. Two weeks ago, another Houston concert was canceled after fans pushed into a Playboi Carti show being held within the same NRG Park complex.