Peco crews are working to restore power to a luxury high rise condominium on Rittenhouse Square that lost its electricity around noon Sunday.

Fred Maher, a Peco spokesman, said an underground cable problem was to blame for the outage at 10 Rittenhouse Square, a 33-story building where six of the 143 units are in the $12-million price range.

Crews hope to have power restored by 11 p.m. Monday, Maher said.

Since many people go away for the Memorial Day weekend, it is not known how many residents were affected by the blackout.

Maher said Peco only counts 47 customers in the building, indicating some owners own multiple units.