Firefighters on Monday morning, Dec. 17 were called out to a residence on S. Marr Street in Fond du Lac for reports of a mattress on fire. The call came in around 5:50 a.m. Careless use of smoking materials sparks mattress fire in Fond du Lac, no one injured. Upon arrival, fire crews entered a a two story, wood framed residence and extinguished the fire before it was able to spread. There were no smoke detectors sounding. All residents safely evacuated the building. The cause of the fire was determined to be careless use of smoking materials. Fond du Lac Fire/Rescue crews will be canvasing the area Monday to educate individuals on the importance of working smoke detectors and fire safety.