The crowd watches as Travis Scott performs at Astroworld Festival at NRG park on Friday in Houston. Jamaal Ellis/Houston Chronicle via AP

HOUSTON — When rapper Travis Scott’s sold-out concert in Houston became a deadly scene of panic and danger in the surging crowd, Edgar Acosta began worrying about his son, who wasn’t answering his phone.

He called hospitals and police, who told him his son was not on the list of victims from the Astroworld festival. They were wrong: Axel Acosta Avila, 21, was among the eight people who died Friday night at the outdoor festival that was attended by some 50,000 people and is now the focus of a criminal investigation.

On Monday, authorities released the names of the dead as they continued looking into what went wrong when a crush of fans pressed forward after Scott took the stage. Houston’s police chief said Monday he had met with Scott before the rapper’s performance on Friday about safety concerns but did not elaborate about what, specifically, concerned him.

“They told me, Mr. Acosta, your son is not on the list so you don’t have to worry about anything. He’s not on the list of dead people or injured people” said Edgar Acosta, whose family is among those suing organizers of the festival.

“I told them, ‘Well, he didn’t spend the night at his hotel, so I’m worried about him.’”

Houston police and fire department investigators have said they would review video taken by concert promoter Live Nation, as well as dozens of clips from people at the show that were widely shared on social media. Investigators also planned to speak with Live Nation representatives, Scott and concertgoers.

Live Nation said in a statement Monday that it has provided authorities with all footage from surveillance cameras at the festival, and that it had paused removing equipment at the request of investigators who were walking the grounds. The promoter said full refunds would be offered to all attendees.

Scott’s scheduled appearance at the Day N Vegas Festival in Las Vegas this weekend was canceled, according to a Scott representative who requested anonymity because they were not authorized to speak publicly about the matter.

Scott, who founded the Astroworld festival, said he would cover funeral costs for the victims. The dead were between the ages of 14 and 27 and were from Texas, Illinois and Washington, according to Harris County authorities. They included high schoolers, an aspiring Border Patrol agent and a computer science student.

Over 300 people were treated at a field hospital on site and at least 13 others were hospitalized. Houston Police Chief Troy Finner said his meeting with Scott before the show included the rapper’s head of a security. But Finner did not go into detail about their conversation in a statement released by the police department.

“I asked Travis Scott and his team to work with HPD for all events over the weekend and to be mindful of his team’s social media messaging on any scheduled events,” Finner said. “The meeting was brief and respectful, and a chance for me to share my public safety concerns as Chief of Police.”

Investigators were also interviewing witnesses and planned to examine the design of safety barriers and the use of crowd control at the event.

“It’s not the crowd’s fault at all, because there was no way you could even move, it was just like a mass loss of control,” said 19-year-old festivalgoer Ben Castro. He returned to the venue Monday to leave flowers at a makeshift memorial that included notes, T-shirts and candles. He said he didn’t know anyone had died until the next day.

Medical examiners have still not released the causes of death, which could take several weeks, said Michele Arnold, a spokeswoman for the Harris County Institute of Forensic Sciences.

Contemporary Services Corp., headquartered in Los Angeles, was responsible for security staff at the festival, according to county records in Texas. The company describes itself online as being “recognized worldwide as the pioneer, expert and only employee owned company in the crowd management field.” Company representatives have not responded to emails and phone messages seeking comment.

Astroworld’s organizers had laid out security and emergency medical response protocols in festival plans filed with Harris County. A 56-page operations plan, obtained by AP, states “the potential for multiple alcohol/drug related incidents, possible evacuation needs, and the ever-present threat of a mass casualty situation are identified as key concerns.”

The plan instructs staff to “notify Event Control of a suspected deceased victim utilizing the code ‘Smurf’.” It goes on to say, “never use the term ‘dead’ or ‘deceased’ over the radio.” It’s not clear whether the protocol was followed.

None of the people listed in charge of managing Astroworld’s security and operations have responded to requests for comment.

There is a long history of similar catastrophes at concerts, as well as sporting and religious events. In 1979, 11 people were killed as thousands of fans tried to get into Cincinnati’s Riverfront Coliseum to see a concert by The Who. Other crowd catastrophes include the deaths of 97 people at a soccer match in Hillsborough Stadium in 1989 in Sheffield, England, and numerous disasters connected with the annual hajj pilgrimage in Saudi Arabia.