Nine people reportedly suffered from a drug overdose in Isla Vista Thursday night around 10:30.
Santa Barbara County sheriff's deputies, fire personnel, and paramedics were called to the scene.
A multiple casualty incident was declared, requiring more emergency workers.
All the victims were male; the drug they used has not been identified.
Narcan, a nasal spray that counteracts the effects of a drug overdose, was used on one of the victims.
The patients were taken in several units to Goleta Valley and Santa Barbara Cottage hospitals.
All nine patients are expected to survive.