The Consumer Electronics Show (CES) in Las Vegas is one of the largest annual technology conferences in the world. But on Wednesday, the power went out in the main hall of the Las Vegas Convention Center. And when a lot of tech needs to be powered, that is...a bad thing.

According to the convention center, 3,900 companies are exhibiting this year and will launch some 20,000 new products. CES's website says that 180,000 people attended the convention in 2017. Companies pay thousands of dollars to exhibit, and the lowest ticket price for admittance is $300.