Rancho Cucamonga , Alta Loma and Etiwanda were most affected by the October 2003 Grand Prix fire , which combined with the Old Fire . The Grand Prix fire , which began October 21 , 2003 , ripped across the mountains just above and , in some places , down into Alta Loma and Etiwanda for six days . Overgrown brush fueled fire , which ran across the mountain tops and higher foothills to eventually fly into the canyons that are surrounded by homes . It destroyed 13 homes ( including 2 mobile homes ) and five outbuildings , and damaged 9 others in Alta Loma
Old Fire
Old Fire
Alta Loma, Rancho Cucamonga, California