Nearly 20 people were treated for a chemical exposure at a swim school in Thousand Oaks Wednesday night that left 12 hospitalized, according to the Ventura County Fire Department.
The VCFD labeled the incident a Mass Casualty Incident. The VCFD said that it was unclear how many people were affected, but eight patients were considered to be "immediate" and seven people were considered to be "minor" in terms of treatment.
Up to nine ambulances responded to the scene, and an investigation into why the fumes from the pool chemicals caused the reaction was underway per VCFD.
The incident took place at Daland Swim School on the on the 100 block of East Wilbur Road in Thousand Oaks.
Paramedics on the scene set up a triage center to treat the people affected at the swim school initially. The patients requiring treatment at a hospital were taken to Simi Hospital and Los Robles Hospital per VCFD.
The fire department said that everyone at the swim school was being assessed for the exposure and being cleared medically before being released. As such, there was no official number of people affected by the chemical exposure.