World Bulletin / News Desk 

A major power outage hit Washington, D.C., on Tuesday, plunging many government and privately-owned buildings into the dark.

The White House, State Department and Smithsonian museums were among key Washington locations affected by the early afternoon outage, but commuter rail service continued in the region, albeit with some stations operating on backup power.

White House spokesman Josh Earnest told reporters that the outage "did briefly have an impact" on the White House complex, forcing some buildings to go on backup power, "but some of the issues have been addressed in such a way that we're now back on the regular power source."

Earnest, who was in a meeting with President Barack Obama in the Oval Office when the outage occurred, said Obama was not affected, and that it was only after he left the meeting that he discovered that there was an electrical issue.

The power went out during the daily State Department briefing as spokesperson Marie Harf was forced to conduct the press conference using light from a cell phone to answer questions from reporters. The briefing was later suspended altogether.

Pepco, the district’s electric service provider released a statement about the cause of the 129 active outages affecting 2,179 customers,

The outrage, which started shortly before 1 p.m. was "caused by an issue with a transmission line," Pepco said in a statement. "There was never a loss of permanent supply of electricity to customers.”

The company said crews are onsite and investigating the cause.

Hashtag #dcpoweroutage quickly became popular on social media and ranked the most popular hashtag on Twitter in the U.S. capital during the outage.

Users shared pictures of their personal experiences, especially in traffic and on school campuses.

Some warned of potential crimes due to the power cut, but many criticized the district’s infrastructure. “The capital of the U.S., a 1st World country with a 3rd World infrastructure,” tweeted one user.

The Department of Homeland Security said there is no reason to believe the power failure is connected to terrorism or other criminal activity.