The incident was first reported at 5:30 p.m. when deputies were called for a report of a fight between people in the area.
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Shots were fired during the fight and an adult male was shot and killed, according to the sheriff. Two stabbing victims were reportedly airlifted to local hospitals with serious injuries, but their conditions are unknown.
The sheriff's office says multiple other stabbing victims were being treated at local hospitals but the number of victims is unknown at this time.
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No arrests were immediately reported. The investigation is being led by Napa County Sheriff's detectives.
This location is a popular recreation area and known for swimming and fishing spots.
Stay with ABC7 News for the latest details on this developing story.
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