The Kansas City Chiefs are on a roll. They're 6-0, and this Sunday at Arrowhead stadium Chiefs fans set the Guinness World Record for loudest crowd in an indoor stadium at 137.5 decibels. If you're wondering how loud that is, it's comparable to a jet engine, which is 140 decibels. Chiefs fans are everywhere right now, proudly supporting their team. But it wasn't that long ago the Chiefs weren't so well represented.