SAN RAMON-- Three adults and one child were displaced from a San Ramon apartment building Thursday morning after a kitchen fire burned two apartments, according to a spokesperson for the San Ramon Valley Fire District.

Fire crews responded at 9:14 a.m. to the Country Brook Apartments at 12355 Alcosta Blvd. after a neighbor called to report they saw smoke coming out from under the door of a second-level apartment, said Kim French, spokeswoman for the San Ramon Valley Fire District.

Three engines and two trucks arrived on scene and found that the fire had broken out in the kitchen of the apartment below, Unit 303, and that the fire had spread to above Unit 307 through the ventilation system, French said.

The two adults and small child who lived in the upper apartment were home at the time of the fire and escaped without injury, French said, as did the resident who lived alone below. Firefighters knocked down the flames at 9:31 a.m.

According to French, the four residents will receive help finding a place to stay while their homes are remediated. In the interim, the American Red Cross will help with temporary living quarters, she said.

The cause of the blaze was determined to be a cooking fire on the stove in the lower unit, French said. Damage to the two apartments was estimated at $20,000, about $15,000 to the building and $5,000 to the residents' belongings.

Contact Erin Ivie at eivie@bayareanewsgroup.com. Follow her at Twitter.com/erin_ivie.