Fire Safety Science Digital Archive

While large wildland fires make news, many are unaware that local U.S. fire departments responded to an estimated average of 356,800 brush, grass, or forest fires (collectively called wildfires) per year during 2004-2008. Wildfires accounted for 23% of fires handled by local fire departments. Three-quarters (74%) of these fires burned less than one acre. Using data from the National Fire Protection Association’s (NFPA’s) annual fire department survey and the U.S. Fire Administration’s (USFA’s) National Fire Incident Reporting System (NFIRS), this paper examines the causes and circumstances of these fires. Wildfires handled solely be federal agencies are not included in these estimates. Nine percent, or an average of 31,700 wildfires per year, occurred at one- or two-family homes. During 2004-2008, 4,800 buildings, on average, were involved annually in wildfires handled by local fire departments. The leading causes of these fires were intentional (20%), hot embers or ashes (17%), outside fires for debris or waste disposal (15%), high wind (13%), smoking materials (12%), playing with heat source (6%), fireworks (5%), and lightning (4%). The cause profile varies by type of fire and type of material first ignited. Lightning caused 15% of the forest fires but only 4% of wildfires overall. Landscaping choices can influence the probability of both fire and fire spread. Mulch fires have become a concern.