CHICAGO (CBS)– Chicago police say arson was the cause of a fire at a school in Marquette Park Friday night.

The fire started at Excel Academy of Southwest Friday night near 70th and Washtenaw.

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Police and fire crews were looking into how a fire started in one of the rooms.

Police told CBS 2 someone broke in and set the fire around 7:30 p.m.

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Fire crews kept the fire confined to one room.

No one was hurt.

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This is a developing story.