One person died in a fire at a fourplex in Martinez early Wednesday morning, a Contra Costa County Fire Protection District spokesman said.

The fire was reported shortly before 3 a.m. at a residential building in the 100 block of Foster Street.

Firefighters arrived and found someone at the back window of a second-floor unit who was unable to get out and was too high up to jump, so crews used a ground ladder to rescue the person, fire district spokesman Steve Hill said.

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A second person was found in the unit and authorities began CPR, but eventually pronounced the person dead at the scene, Hill said.

The fire was controlled as of about 3:15 a.m.

Investigators learned that someone was cooking in the kitchen of the unit when the fire started, but the exact cause of the blaze remains under investigation, according to Hill.

Eight were displaced from the building and the American Red Cross is assisting them, Hill said.