SAN FRANCISCO (CBS SF) — A power outage in San Francisco left hundreds of homes and businesses in the Financial District in the dark.

The outage was first reported at 8:49 p.m. on Monday.

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PG&E confirmed the outage was due to underground equipment failure during planned maintenance work. There was a report of a blown manhole cover at Lombard and Sansome streets. Emergency personal were on the scene.

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Some 289 customers were affected by the outage.

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According to PG&E, power was restored to all but 2 customers by 10:15 p.m.