Last-minute Christmas shoppers were faced with an unexpected obstacle Sunday afternoon: The King of Prussia Mall - the largest shopping complex on the East Coast - went dark after a circuit providing power to it had a momentary outage, according to officials.

The outage occurred around 2:15 p.m., Peco spokesman Greg Smore said. The issue was resolved quickly on the back end, because the utility's system is designed to immediately switch problematic power lines to working lines within a few seconds, Smore said.

It took about a half-hour for the mall to regain power fully, said King of Prussia Mall marketing director Kathy Smith, who added that the outage affected about 50 of the mall's 400-plus stores.

Smith said that there were no security incidents reported during the outage, and that the mall was to remain open as usual through Sunday night.

Some customers took to social media Sunday afternoon, writing about their experience shopping in the dark.

One Facebook user, identified as Phil C, streamed live video from the mall during the outage. After about eight minutes, he can be heard talking to someone who said the "whole mall" was shutting down, and he left to head out to the parking lot.

Smith said the mall did not officially close, though she did say that affected stores may have appeared to shut down because their point-of-sale services were not functioning without power.

Another Facebook user, Anthony Joseph, wrote at 2:24 p.m.: "About 90% of kop mall is out of electricity," though officials said the impact was not that widespread.

No social media users posted about significant mayhem or problems; some even tried to make light of the situation.

One Twitter user, identified only as Con Sweet Con, wrote: "Hey @KoP_Mall kind of dark in here. Can't we get some lights???? Pay that bill."