At least 8 people were killed and hundreds more were injured at Astroworld music festival in Houston on Friday night after a large crowd began pushing toward the front of the stage, the city’s fire chief reported at a news conference.

The crowd surge, during a concert by the rapper Travis Scott, “caused some panic, and it started causing some injuries,” said the fire chief, Samuel Peña. The concert was part of the Astroworld music festival, a 2-day event that began on Friday. About 50,000 people were there on Friday night, according to the fire department.

“It was like hell,” said Nick Johnson, 17, who still had his concert bracelet on as he spoke Saturday morning. “Everybody was just in the back, trying to rush to the front.”