It happened on Glenwood Avenue at Vick Road, where a massive tree is blocking the road.
Glenwood is closed in both directions.
Crews were working to clear the area, but repairs were taking longer than first expected.
At 11 p.m., workers were still at the scene, and the estimated time of restoration was 2 a.m.
The outage comes amid dangerously hot weather.
Police officers are redirecting traffic in the area, as some traffic lights have been affected.
It's still unclear what caused the tree to topple.
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