It interrupted a State Department briefing and forced the White House onto back-up generators . Outage 'briefly had an impact on the White House complex ' but it was 'back on the regular power source ' an hour and a half later . White House press secretary says he was in the Oval with the president when it happened , and it was barely noticeable . Related to a dip in power in a transmission line at a D.C. facility , power company says ; another report says it may have been an explosion . Homeland Security says there 's no evidence of malicious activity .
It interrupted a State Department briefing and forced the White House onto back-up generators . Outage 'briefly had an impact on the White House complex ' but it was 'back on the regular power source ' an hour and a half later . White House press secretary says he was in the Oval with the president when it happened , and it was barely noticeable . Related to a dip in power in a transmission line at a Maryland facility , power company says ; another report says it may have been an explosion . Homeland Security says there 's no evidence of malicious activity .