VACAVILLE (CBS13) – A 17-year-old is under arrest for allegedly starting a five-alarm fire in Vacaville on the Fourth of July.

The Pena Adobe Fire scorched more than 325 acres near Lagoon Valley Park.

Fire crews say they spotted a group walking through the park shortly after the blaze started.

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Investigators from the Vacaville Police Department and Cal Fire have been in contact with the group and eventually identified a juvenile suspected of starting the fire.

Thursday, the teen was arrested at a home in Fairfield. The teen, whose identity is not being released, has been booked at Solano County Juvenile Hall and is facing a charge of causing an unlawful fire to forest land.

It took a hundred firefighters from several agencies several hours to contain this blaze.