A Nebraska grass fire that has destroyed thousands of acres was moving at up to 45 mph, fueled by searing temperatures and gusting winds, officials said. However, a US Forest Service official estimates of the size of the fire has been halved from 100,000 acres to 80,000 acres, which is about 80 square miles, the Lincoln (Neb.) Journal Star reported Tuesday. \"(The flames) move at 40 to 45 miles per hour across the flat ground,\" Region 24 Emergency Commander Doug Fox told KBRB radio in Ainsworth, Neb. \"When the grass is short, it really gets cranking.\" Lightning is suspected as the cause of the fire that started Sunday and moved quickly through the forests and grassland along the Niobrara River. The village of Meadville was evacuated and the small community of Sparks may also be put under an evacuation order, Ainsworth Fire Chief Brad Fiala told KBRB. In Arizona, at least eight wild fires were burning west of the Kaibab Plateau near the Grand Canyon. The fires, dubbed the West Side Complex, had burned 2,781 acres as of Monday morning, The Arizona Republic said. Lightning is also suspected in the Arizona fires, officials said. The largest fire in the complex, the Tank Fire, was about 50 percent contained Monday.