We’re learning what caused an underground fire Monday morning near Kiowa and Nevada in the downtown area. Colorado Springs Utilities say the blaze was caused by a failed underground electrical vault and that there were no red flags indicating the underground transformer was in need of repair. Meanwhile, witnesses reported seeing manhole covers pop off and flames as high as 10 feet shooting up from the ground. Officials with the Colorado Spring Fire Department say this is designed to relieve pressure and keep the sidewalk from collapsing. Hundreds of CSU customers across the city were left without power because of the blaze. Officials say there are still some waiting to get their power restored.