Authorities to investigate the causes behind a deadly crowd at the Astroworld festival in Houston

(CNN) – Following the crowds at the Astroworld concert in Houston that left at least eight dead and dozens injured, authorities will examine the root causes of the crush and what could have been done to keep attendees out of harm’s way, police said Saturday .

On Friday night at the Astroworld festival, the crowd was so compressed that when attendees were pushed onto the stage, some told CNN they were crushed against each other to the point of being unable to breathe and passed out.

Local authorities have vowed to launch an investigation into what led to the tragedy at the music festival spearheaded and hosted by rapper Travis Scott, saying they will review videos of the scene and assess how the venue was laid out.

The investigation will cover “what caused, one, the crowding issue, and, two, what prevented people from escaping that situation,” Houston Fire Chief Sam Peña said Saturday.

The homicide and narcotics divisions of the Houston Police Department are involved in the investigation, but the investigation is not being treated as a criminal one, police said.

“We are certainly looking at all the video footage, we are talking to witnesses, we are talking to the organizers of the event,” Houston Mayor Sylvester Turner told CNN on Saturday. “This happened at one of the county facilities last night, so we’re looking at everything.”

The chaos sent at least 25 people to the hospital, and 13 of them remained there Saturday afternoon, Turner said. Five of them are under the age of 18, he added.

The ages of the victims who died range from 14 to 27, and the age of a person who died remains unknown, Turner said.

The causes of their deaths are pending the determination of the forensic doctor, said Peña.

With 50,000 people in attendance at NRG Park – the stadium complex where the Astrodome and NRG Stadium are located – the crowd began to develop after 9 pm CT on Friday.

“The crowd, for whatever reason, started to push and move towards the front of the stage, which caused the people in the front to look tight; they couldn’t escape from that situation,” Peña told CNN.

Scott was on the outdoor stage when he stopped and looked at the crowd in confusion as an ambulance with flashing lights moved through the audience, according to video from the event.

On Saturday, Scott posted in a story on his Instagram account that he is sending prayers for lives lost, adding that he has collaborated with authorities in Houston.

“I’m honestly devastated,” Scott said as he sighed repeatedly and rubbed his forehead. “In fact, we are working right now to identify the families and be able to help them through this difficult time.”

Astroworld Assistant: “It seemed like we were drowning in a crowded pool”

With dozens of people injured by being pushed onto the stageSome members of the public told CNN that they couldn’t breathe and thought they might die.

Sarai Sierra, who came to the festival to celebrate her birthday, said she saw several people who couldn’t breathe after Scott appeared on stage.

“I really thought that if I fell it would have been the end of me. I spent at least 15 minutes being pushed by groups of people or just because people were ‘angry’,” Sierra said.

Sierra, who attended the festival with friends and family, added that he saw about 20 people who could not breathe, including one person who suffered a seizure before his eyes.

“It looked like we were drowning in a pool full of people only,” he said.

Nick Johnson and Ángel Rodríguez, who also attended the festival, said the crowded atmosphere built up over a long period of time.

“It was going on for more than two hours,” Johnson said. “Every time it was getting worse, everyone was as if they could not breathe, as if they had a heavy blanket over them.”

And once people were pushed onto the stage, breathing became more difficult, Rodríguez explained.

“When they push you back, people always fall,” Rodriguez said.

A security officer fell unconscious

In 2019, the festival dealt with a similar circumstance, as three people were trampled and hospitalized as thousands of people rushed into the festival.

Authorities tightened security after the 2019 hit-and-run incident, assigning 528 Houston police officers to the concert and another 755 private security personnel, Houston Police Chief Troy Finner explained.

Even so, a security officer was hit on the neck during the concert while trying to restrain a member of the audience.

“When they examined him, he was knocked unconscious. They gave him Narcan,” Finner said during a news conference Saturday. “They resuscitated him and the medical staff did notice a prick similar to what would occur if someone tried to inject themselves. That is part of the matter.”

In addition, there were other incidents in which the drug was administered on Friday, Peña said.

Narcan is a drug used to treat narcotic overdoses.

Other attempts to save lives included some people applying CPR. Former marine infant Lucas Naccarati said he performed CPR on two people who passed out.

“That was a different world. I immediately thought, ‘This is not right. Someone is going to die here,'” he told CNN. “I have never seen a massive amount of bodies falling so fast.”

CNN’s Melissa Alonso, Maya Brown, Keith Allen, Jenn Selva, Andy Rose, Artemis Moshtaghian, Jason Hanna, and Claudia Dominguez contributed to this report.