At least eight people died and more than 300 were injured after a crowd surge caused panic at Travis Scott]s’s Astroworld Festival on Friday night in Houston at NRG Park.

Houston Fire Department Chief Samuel Peña called it “a tragic night” for the city. He estimated the concert attendance at 50,000 and said trouble started brewing shortly after 9 p.m. “The crowd began to compress toward the front of the stage and that caused some panic and started causing some injuries. People began to fall out and become unconscious and that created additional panic,” Peña said.

It wasn’t immediately clear what prompted the crowd to start moving toward the stage. Peña said a “mass casualty” incident was triggered at 9:38 p.m., shortly after which his team transported 17 patients to the hospital, 11 of which were in cardiac arrest. Astroworld organizers had a medical tent on-site but Peña said festival staff “were quickly overwhelmed” by the situation, leading his team to step in and dispatch as many as 50 units.

Police are looking into a drug-spiking incident in an area of the festival where the chaos first began. The sources said it appeared to have been targeted at unknowing people, and that the crowd surge may have resulted from panic as attendees ran for safety. Houston Police Chief Troy Finner said during a press conference Friday that authorities have “heard rumors of people injecting people with drugs” at the show.

Concert teams are working to provide police with drone and on-the-ground footage. One of the knowledgeable sources says a 10-year-old child is believed to be among the dead.

“My prayers go out to the families and all those impacted by what happened at Astroworld festival. Houston PD has my total support as they continue to look into the tragic loss of life,” he wrote.

One question raised in the immediate aftermath was why the concert continued after Scott paused the show a couple of times to get help for attendees in distress. A source close to the rapper says he did stop the show once he was informed of the magnitude of the situation.

Videos shared on social media show a chaotic scene.

Early in evening, in separate incident, hundreds of concert-goers toppled steel barricades and stormed through security to access the concert. Later, as the tragedy was already underway, medical personnel can be seen carrying young people out on stretchers and attempting CPR on others. One clip showed Scott still on stage performing as several concertgoers attempted to inform security guards of the emergency.

Friday’s festival lineup featured artists including SZA, Master P, Yves Tumor, Toro y Moi, Roddy Rich, Lil Baby and Scott, who was scheduled to close the night from 8:45-10 p.m. He brought out a surprise guest in Drake.

Astroworld and Live Nation reps did not get an immediate response by early Saturday morning. Some reports have indicated that Saturday’s Astroworld has been canceled.

Peña said the investigation will continue as they attempt to identify patients and casualties. A reunification center has been opened at the Wyndham Houston Hotel for family members who may not have heard from their relatives that attended the show. “We are coordinating with organizers and that will continue to move forward as the hours go by,” he added.

He was joined at the press conference by Harris County Judge Lina Hidalgo, who called it “an extremely tragic night.”

“Our hearts are broken. People go to these events looking for a good time, a chance to unwind, to make memories. It’s not the kind of event you go to to find out about fatalities.”

This year’s event marked the third annual Astroworld put on by Scott, who grew up in Missouri City, outside of Houston. Per organizers, the 2021 edition expanded to two days due to demand. The sold-out event is one of the largest put on by the city.

A statement posted to the Astroworld Fest’s social media early Saturday morning confirmed that day two of the planned event is canceled in light of the tragedy. The statement acknowledges the festival’s organizers are “focused on supporting local officials” at this time and encouraged anyone with relevant information to contact the Houston police.

In a statement posted to the city of Houston’s Twitter account the same day, Mayor Sylvester Turner stated that he has “called for a detailed briefing from all stakeholders including Live Nation, Harris County Energy Park, police fire, Office of Emergency Management and other agencies explaining how the event get out of control, leading to the deaths and injuries of several attendees.”