At around 2.15pm, before the concert, video showed hundreds of people rushing through barriers at a VIP security checkpoint and barging past security.
At least one person was injured in that afternoon scrum.
Houston Fire Chief Sam Pena said that he wasn’t aware of what caused the rush but said that any special precautions for this year’s festival ‘weren’t enough.’
Police Chief Troy Finner visited rapper Travis Scott before his set to express ‘concerns about the energy in the crowd,’ according to the The New York Times.
Scott was due to perform at 9pm. A massive countdown timer came up 30 minutes before his set on a big screen.
ICU nurse Madeline Eskins said that the closer the timer got to zero, the worse the pressure within the crowd became.
‘People compressed up against each other and were pushing forward and backward,’ she told CNN.
Just after 9pm, Scott took to the stage to start his set which also included a surprise appearance by Drake.
By the time the rapper entered the stage people had already started to pass out.
At 9.30pm, officials received the first reports of injuries, Pena said.
At around 9.30pm, an ambulance made its way into the crowd, taking 10 minutes to reach the patient.
Video footage, which has since been deleted, shows two men who appear to be part of Scott’s entourage approach him on stage.
‘Y’all know what you came to do,’ Scott said, turning to the crowd, before the music started up again.
He then asked the tens of thousands in front of him to make ‘the ground shake.’
At 9.38pm, a ‘mass casualty event’ was declared, the fire chief said.
Scott maintains he was not aware of the severity of what was happening but he did stop the show on at least three occasions to ask that stricken people get help.
At around 10.10pm, the performance was finally halted.