Lights go out at the United Center in the middle of the game.

Hockey fans at the United Center were treated to a rare surprised on Monday night.

During the opening period of a game between the hometown Chicago Blackhawks and the visiting Utah Mammoth, those inside the building at the United Center as well as those watching from home were shocked when the lights in the building suddenly went out. There was just under 6 minutes to go in the period when everything in the arena went black, leaving the broadcasters to wonder who had accidentally stumbled into the light switch.

The worst part was that the game was in the full swing of things, with the players out on the ice and in the middle of an active play. Thankfully the officials on the ice were quick to react, blowing the play dead immediately, and no one was injured as a result of the hiccup.

All in all it only lasted a few seconds, but it was enough to provide everyone in the building with a little excitement in what had been a scoreless period up until that point.

You can see the video of the unusual incident just below: