The Long Beach Fire Department said it is investigating whether its employees were among a group of people rushed to the hospital in Santa Barbara County after apparently overdosing on opioids at a party this weekend.

“We are aware of the allegations, and it’s a personnel issue and we’re investigating those allegations at this point,” LBFD spokesman Brian Fisk said.

The Long Beach Post asked the department about the situation after a source with knowledge of the incident said Long Beach firefighters were involved.

The incident happened at a party after a wedding in Santa Barbara County, according to the Santa Barbara County Sheriff’s Office.

About 30 people were at a home that had been rented out for the occasion when someone called 911 around 1:50 a.m. Sunday to report that two people weren’t breathing. Rescuers arrived and found two men and two women who showed symptoms of an opiate drug overdose, according to the department.

Paramedics gave the four people Naloxone Hydrochloride, a drug more commonly known as Narcan, which blocks the effects of an opioid overdose, and took them to the hospital, authorities said.

“The patients are believed to have snorted a white powder from an unknown source,” Sheriff’s officials said in a news release. “No drugs were located inside the residence.”

The news release said all four patients were in their 30s and from Long Beach. Kelly Hoover, spokeswoman for the Santa Barbara County Sheriff’s Office, declined to confirm whether they are members of the Long Beach Fire Department.

“We are not releasing additional information regarding the identities of the four individuals who were administered Narcan because they were not arrested and the call was for emergency medical assistance and falls under 911 drug immunity laws,” Kelly said. People seeking medical attention after an overdose are protected from arrest on most drug charges, according to California law.

The LBFD declined to provide any more details.