HOUSTON (Nexstar) — Houston police chief Troy Finner said a security officer was administered Narcan at Travis Scott’s Astroworld Festival Friday night, according to medical staff on scene.

“We do have a report of a security officer, according to the medical staff, that was out and treated him last night, that he was reaching over to restrain or grab a citizen and he felt a prick in his neck,” Finner said at a Saturday news conference.

The medical staff examined the unconscious security officer and administered Narcan, an emergency treatment for opioid overdoses, Finner said at the press briefing. He added that medical staff noticed a prick on the individual’s neck.

The security officer went unconscious briefly. Medical staff then administered Narcan, an emergency treatment for reversing opioid overdoses, and he was revived. Finner said medical staff did notice a prick on the officer’s neck, “similar to a prick that you would get if somebody is trying to inject.”

Narcan is a nasal spray or can be injected to any person who shows signs of an opioid overdose, according to the National Institute on Drug Abuse. It attaches to the opioid receptors, reversing and blocking their effects. Examples of opioids include heroin, fentanyl, oxycodone, hydrocodone, codeine, and morphine.

Houston officials did not have an exact count of how many Narcan administrations occured at the festival, but said they have heard of “several” from medical staff on scene Friday night.

The police chief acknowledged there are “a lot of narratives out there.” While officials cautioned people not to buy into every rumor on social media, they said “nothing is off the table” when it comes to the investigation.

“We will leave no stone unturned. This has not happened to us ever in Houston since I’ve been a police officer,” Finner said. “I think that all of us need to be respectful of the families and make sure that we follow the facts and evidence.”

In addition to the security officer incident, at least eight people have died and around 300 were injured in the mass “panic” that occurred during Scott’s performance Friday night. Twenty-five people were treated at hospitals, and officials confirmed a 10-year-old was in critical condition, as of Saturday.

The ages of the victims who died range from 14 to 27.

Houston Mayor Sylvester Turner said reports of individuals at the concert falling and getting injured were made known around 9:30 p.m. Friday and organizers ended the event roughly around 10:10 p.m, and canceled Saturday’s concert.

Some eyewitnesses said the event seemed “understaffed” in comparison to the estimated 50,000 attendees at the sold-out venue of NRG Park Stadium. Houston leaders say fire and EMS units were stationed around NRG Park Stadium and acted quickly to help, with 62 units responding.

Houston fire chief Samuel Peña said a third-party contractor was handling the medical needs for Astroworld, but couldn’t speak to whether they were equipped to handle the surge of attendees needing treatment.

“They had doctors on scene, they had medical EMTs, they had volunteers,” Peña said during a press conference Saturday. “For a non-event, that would’ve been enough. But when the event started to escalate, we had to come in and augment their assistance.

Authorities did not know the immediate cause of death of the 8 individuals confirmed dead. Medical examiners with Harris County are working on autopsies, according to officials.