SAN PABLO, Calif. (KGO) -- Contra Costa firefighters are investigating the cause of a two-alarm fire at a senior housing complex on Saturday.
The fire happened on the second floor of the Montevista Senior Apartments in San Pablo.
MORE: 1 killed, 1 injured in early morning East Bay apartment fire
One person was treated for smoke inhalation, firefighters said.
The damage to the unit where the fire started is "substantial," crews said.
Some residents are displaced, but it's unclear how many.
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