One youth and six staff members at Los Padrinos Juvenile Hall in Downey were taken to local hospitals Wednesday morning after a suspected overdose and the possible exposure to an “unidentified substance,” authorities said.

Staff at the troubled juvenile hall administered Narcan, typically used to reverse the effects of fentanyl, before emergency personnel arrived.

All but one male staff member had been discharged from the hospitals as of Wednesday evening, according to Vicky Waters, a spokesperson with the Los Angeles County Probation Department. She said the staffer is in stable condition.

Hospital testing is underway to determine what substance the seven individuals were exposed to, according to Waters. Earlier in the day, hazmat teams were on site at Los Padrinos assisting emergency teams to try to figure out what the substance was.

Waters said the detention center, which houses about 270 juveniles, remains on lockdown with limited programming until further notice.

“Tomorrow, depending on the investigation, it will be determined if limited programming will continue through the week,” she said. “Staff is continuing to search the units.”

The Probation Department has been struggling for years to stop the flow of drugs into its detention facilities.

In March 2023, the L.A. County Office of Inspector General found pervasive security flaws — worsened by the Probation Department’s chronic staffing issues — at the county’s two juvenile halls at the time. Investigators determined that drugs were thrown over the fences, dropped by drones and even brought in by fake delivery drivers.

Two months later, an 18-year-old detainee died from a fentanyl overdose at the Barry J. Nidorf Juvenile Hall in Sylmar. Bryan Diaz of Wilmington had been at the facility for only about six weeks at the time. Before the end of 2023, six more youths were hospitalized from drug overdoses.

Although probation officials have vowed to crack down on drug smuggling into its detention facilities, the problem persists.

In April, three youths at Los Padrinos were rushed to a hospital for suspected drug overdoses but returned the same evening after undergoing routine medical observation. Similar to what occurred Wednesday, the facility was placed on a modified schedule in which visits were canceled and the movement of detainees was restricted.

At that time, the Probation  Department said it was “committed to a thorough review and will take all necessary steps to prevent incidents of this nature in the future.”

In June, a deputy probation officer was charged with smuggling Xanax into the Nidorf Secure Youth Treatment Facility and working with a youth in custody to sell it.