The Santa Barbara County Sheriff's Office says nine Isla Vista residents with drug overdose symptoms were sent to hospitals.
The incident unfolded Thursday night in the community adjacent to the University of California, Santa Barbara.
The Sheriff's Office initially said all were UCSB students but later said some were not, but did not give a breakdown.
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Deputies, UCSB police officers, firefighters and paramedics summoned to a residence found an unconscious male in a vehicle. Housemates said he had ingested alcohol and Oxycontin.
After that person was taken to a hospital, deputies found another who wasn't breathing. A deputy gave him a dose of an anti-opioid spray and he resumed breathing. Seven other people were also transported.
Eight have been released and the ninth was expected to be released.