A source tells PEOPLE that the expectant mother and her sister, Kendall Jenner, are both okay and did not get injured in the incident at NRG Park.
"Everyone is shocked and upset," the insider says. "Kylie and Kendall were in the audience, but they are not injured."
"Travis won't be performing tonight. The concert is canceled," the source adds.
Early on Saturday morning, Houston Fire Chief Sam Pena provided details regarding the incident in a press conference.
"We had at least eight confirmed fatalities tonight. Eight confirmed fatalities and we had scores of individuals that were injured here at this event," Chief Pena said. "We had an attendance of approximately 50,000 to the Travis Scott Astroworld Festival event."
"What we do know is that at approximately 9 o'clock, 9:15, the crowd began to compress towards the front of the stage and that caused some panic and it started causing some injuries," he continued. "People began to fall out, become unconscious, and it created additional panic."
Chief Pena noted that 17 individuals were transported to hospitals. "12 of those patients were transported by Houston Fire Department ambulances, five were transported by Harris County emergency services, 11 of those that were transported were in cardiac arrest," he said.
"We won't know the cause of death of the eight that are confirmed until the medical examiner has completed his investigation, but we are in the process," Chief Pena added. "The Houston Police Department is sending units out to the hospitals to identify these patients, these fatalities."
A reunification center for event attendees has also since been set up at the Wyndham Houston Hotel.
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Jenner confirmed her pregnancy news in September.