Electricity has been a fact of life for almost a century and a half, but apparently we’re still working out the kinks.

A number of power outages were reported Wednesday at the Las Vegas Convention Center, where CES—the world’s largest annual showcase of tech and gadgets—has been underway since Monday. Event organizers called the outage “isolated” in a tweet as attendees flooded Twitter with images of darkened exhibition halls and befuddled crowds. The hashtag #CESblackout was the top U.S. Twitter trend as of late Wednesday afternoon.

There is an isolated power outage at the Las Vegas Convention Center. We are working hard to resolve this and appreciate your patience. — CES (@CES) January 10, 2018

Per the BBC, attendees were evacuated from the affected space, which included booths for LG, Samsung, Sony, and others.

At least some brands took it in stride. Check out the tweet below from Intel.