A failed breaker is blamed in a power failure that affected 6,600 Westar Energy customers for about three hours late Thursday night.

Westar Energy spokeswoman Gina Penzig said power was restored to all customers by 12:05 a.m. today.

Penzig said it’s unclear why the breaker failed, but it’s not believed to be weather-related. “Sometimes those things just happen,” Penzig said.

The power failure was reported at 8:55 p.m. after a problem at a Westar substation near 23rd Street and O’Connell Road.

The affected area stretched from 19th Street to North 1100 Road and east to Eudora.