A grass fire tore through a field in western Colorado Springs and sent firefighters scrambling to protect nearby houses on Tuesday afternoon. The fire was reported around 1:30 p.m. north of Mesa Valley Road and east of Centennial Boulevard and it quickly threatened houses in the area, said Capt. Steve Oswald, a Colorado Springs Fire Department spokesman. Firefighters knocked the fire down roughly 20 minutes later, Oswald said. He hesitated to say the fire was under control at 1:55 p.m., because firefighters were still putting out hot spots and setting up a perimeter.