Houston Police Chief Troy Finner speaks during a press conference at the Wyndham Hotel in Houston, Texas, the United States, Nov. 6, 2021. The investigation into the stampede leaving eight people dead and many others injured Friday night at the Astroworld Festival in Houston was underway, Houston Mayor Sylvester Turner said Saturday afternoon. Photo: Xinhua

 

Houston Mayor Sylvester Turner speaks during a press conference at the Wyndham Hotel in Houston, Texas, the United States, Nov. 6, 2021. The investigation into the stampede leaving eight people dead and many others injured Friday night at the Astroworld Festival in Houston was underway, Sylvester Turner said. Photo: Xinhua

 

Houston Fire Department Chief Samuel Pena speaks during a press conference at the Wyndham Hotel in Houston, Texas, the United States, Nov. 6, 2021. The investigation into the stampede leaving eight people dead and many others injured Friday night at the Astroworld Festival in Houston was underway, Houston Mayor Sylvester Turner said Saturday afternoon. Photo: Xinhua

 

Flowers are laid outside NRG Park, the site of a stampede during the Astroworld Festival, in Houston, Texas, the United States, Nov. 6, 2021. The investigation into the stampede leaving eight people dead and many others injured Friday night at the Astroworld Festival in Houston was underway, Houston Mayor Sylvester Turner said Saturday afternoon. Photo: Xinhua

 

Mourners pay respect outside NRG Park, the site of a stampede during the Astroworld Festival, in Houston, Texas, the United States, Nov. 6, 2021. The investigation into the stampede leaving eight people dead and many others injured Friday night at the Astroworld Festival in Houston was underway, Houston Mayor Sylvester Turner said Saturday afternoon. Photo: Xinhua

 
The investigation into the stampede leaving at least eight people dead and many others injured on Friday night at the Astroworld Festival in Houston, U.S. state Texas, has been underway, Houston Mayor Sylvester Turner said on Saturday afternoon.

"This incident is being thoroughly investigated and reviewed thoroughly. It is important for us to ascertain from last night what took place, what happened, where missteps may have occurred," Turner said at a press conference.

Seven of the eight dead aged from 14 to 27 years old, said the mayor. The eighth's age is not yet available at that time. No one has been reported missing from the concert.

Up to 25 people had been transported to the hospital following the incident, and 13 of them were still being hospitalized, including five people under the age of 18, according to the mayor.

The patients also included a 10-year-old child who was in critical condition, according to media reports.

"Organizers held the event to bring people together for music, but it sadly ended in tragedy," the mayor said on Twitter.

Investigators will review video from the scene and look at how the venue was laid out and whether it had enough exit points so as to explore "what caused, one, the issue of the crowd surge, and two, what prevented people from being able to escape that situation," said Chief of the Houston Fire Department Samuel Pena.

"The crowd began to compress towards the front of the stage and that caused some panic and it started causing some injuries," Pena told a press briefing early Saturday morning.

The tragedy occurred just after 9 p.m. CT as rapper Travis Scott was on stage at the sold-out outdoor music festival with about 50,000 attendees on Friday night.

Video from the event showed Scott paused and looked on in confusion during the performance as an ambulance with flashing lights moved into the densely packed crowd.

"The crowd was squishing me so much that I felt like I couldn't breathe," Emily Munguia, 22, told CNN. "I started screaming for help ... I felt so scared, like I was going to die."

"I'm absolutely devastated by what took place last night. My prayers go out to the families and all those impacted by what happened at Astroworld Festival," Scott tweeted on Saturday.

More than 300 people were treated at a field hospital set up near the festival, Pena said earlier on Saturday.

The causes of deaths are pending the medical examiner's determination, according to city officials. The second night of the concert was canceled in the wake of the incident.

The Astroworld music festival began in 2018 and was canceled in 2020 due to the COVID-19 pandemic.

Houston, the most populous city in the U.S. state of Texas, is also the principal city of the Greater Houston metropolitan area.