Winfrey was part of the dedication ceremony of a new U.S. Postal Service Forever Stamp that honors Angelou.
"I am honored to be here to stand her as her daughter, sister-friend at the unveiling of the Maya Forever-- FOREVER-- stamp," Winfrey said, and then the lights went out.
"No doubt about it-- no doubt about it, she was a phenomenal woman," Winfrey continued.
CLICK ON THE PLAYER ABOVE TO WATCH THE VIDEO!
The room was packed, and First Lady Michelle Obama was among those in attendance.
The widespread power outages affected parts of D.C. and Maryland, and are being attributed to a transformer fire and explosion in Charles County, Maryland, according to fire officials. The White House and parts of the Capitol and some Metro stations and museums in the District were without power for a time. The Department of Homeland Security says there's no indication that the outages are related to any malicious activity.
Click here for updates on the investigation into the outages.