The fire in the 600 block of Sycamore Street was first reported to dispatch around 10:30 a.m. by an engine company in the area after responding to a different call.
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An arson investigator responding to the scene determined that the fire appears to have started in one of the tents before spreading to two others, then the vehicle, according to Battalion Chief Zoraida Diaz.
"It burned the tires, went underneath the undercarriage and into the cab," Diaz said.
"You could tell that there was stuff in it, but we don't know if it was someone was actually living in it," she added.
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The cause of the fire is still under investigation, but the arson investigator was sent to the scene per departmental protocol for any blaze involving a homeless encampment.
"He's still investigating, and he comes out to any incident that involves tents," Diaz said.
Four people were displaced as a result of the fire, but no injuries were reported. The American Red Cross is assisting the individuals displaced.