An outage knocked out power to Westchester Medical Center in Valhalla for hours on Friday.

A spokesman for Westchester Medical says the facility lost electricity around 3 a.m. Most of the facility, including the ER, was working off of emergency generator power during the outage.

The adjacent Maria Fareri Children's Hospital and the Behavioral Health Center also lost power, but patients at all the affected facilities were safe and continued to receive care, officials say.

Power returned Friday afternoon. It is unknown what caused the outage at this time.

Con Edison had said the problem wasn’t on its end, and that an internal problem within the facility was likely to blame.

The hospital had canceled all elective procedures due to the outage.