The death count from the stampede at Travis Scott’s Astroworld concert could rise above the eight already confirmed, Houston Fire Department Chief Samuel Pena said Saturday.

11 people suffered cardiac arrest from the 23 people who were brought to the hospital by authorities following what they initially called a crushing accident Friday night at NRG Park, Houston.

“What we know is that we have eight people who have died as a result of the injuries suffered at at that event,” Pena told MSNBC Saturday. “That number may rise, because we did transport more people in critical condition. We took 11 that they were performing CPR on en route to the hospital.”

NRG Park saw 300 additional patients. The chaotic atmosphere was a sign that the medics on site were not well prepared and ill equipped for such large-scale operations. Pena stated that LiveNation provided security and medical care for the concert.

The Houston FireAnd Police Departments posted appeals Saturday morning asking for anyone still searching for loved ones to contact the family reunification centre at a nearby hotel. This suggests that some victims may not have been identified.

Pena reacted to criticisms about the concert’s continuation after it became clear that there were problems among the crowd. Pena said Scott and LiveNation made the call to stop the performance — and cancel Saturday’s program. “They did decide to to essentially pull the plug on it when the when the situation started to escalate,” he said.

Pena said it’s still too early to make any conclusions about what triggered the tragedy. A medical examiner’s determination of the causes of death among the victims will be a key to learning if something other than a crowd crush was involved.

“This is a this investigation is still in its infancy,” he told MSNBC. “We don’t know what what caused it.” There were an estimated 50,000 people in crowd for the sold-out show.

“It was just, I think, a matter of people trying to push towards the front and get towards the front,” he said. “That’s what I envisioned.” The probe will examine the layout of the venue and consider whether there were enough ways for people to move in and out, he said.

“We will be dissecting this thing in its entirety,” Pena said. “I’ve been doing this for 27 years and I have never seen something like this.”