Tuesday's grass fire is being listed as "suspicious" by Wichita Falls Fire Fighters until a cause can be determined.
Crews spent the night monitoring the area for hot spots. The fire started behind the homes off Lantana Drive just before 4 Tuesday afternoon, burning about 40 acres.
Officials say they were able to determine where the fire started but not how. Fire officials say rather than wasting water, they allowed the remaining hot spots to burn themselves out.