MILLBRAE (CBS SF) — A San Mateo County Sheriff’s Office deputy was treated for smoke inhalation injuries after helping rescue residents from a three-alarm fire at an apartment complex in Millbrae on Monday afternoon.

The fire was first reported at 12:36 p.m. at 1007 Hemlock Ave., sheriff’s officials said. Deputy Edgar Manilla helped a resident and her two children escape the blaze and then got two elderly residents out of their residence.

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Manilla stayed at the scene to help, but was eventually transported to Mills Peninsula Hospital. He is assigned to the Millbrae Police Bureau.

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Sheriff’s officials said all the residents of the apartment complex were displaced and receiving assistance from the American Red Cross.

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The Central County Fire Department received help from the San Bruno and South San Francisco fire departments in extinguishing the blaze. The cause of the fire is under investigation.