Pepco, the D.C. electric services provider, initially said it had scattered reports of outages for "unknown" reasons, and that it was looking into the matter. Government officials later pointed to an explosion at a southern Maryland power facility as the likely cause for the regional issue.
Department of Homeland Security officials said just after the outage began that they were looking into the outage, but believed at the time there was no reason to believe the power failure had any connection to terrorism or other criminal activity.
The utility company said in a 1:35 p.m. ET update that it recorded 129 active outages and 2,179 affected customers (which include buildings and office spaces). Pepco told CNBC that a brief dip in D.C. area voltage caused some customer's systems to automatically switch to a backup system—there was never any full loss of electricity and customers could resume use of street power whenever they wanted, it said.