On 12/30/16 at approximately 2345hrs, Humboldt Bay Fire responded with 3 engines, 1 ladder truck, 1 Squad and 2 Chief Officers to a reported Commercial Structure Fire @ 12 W. Waterfront Dr. First arriving units reported smoke was visible from the building and access was made through locked gates onto the property and fire was visible to the rear of the building. Defensive operations were initiated utilizing elevated master streams and large diameter hose lines. A 2nd and 3rd alarm was requested and the Humboldt Bay Harbor District fire boat was also requested to the scene. Off duty Humboldt Bay Fire personnel responded in addition to units from Arcata, Samoa-Peninsula, Blue Lake, Fortuna, Loleta and Cal Fire. The fire was controlled in approximately 3 hours and one firefighter sustained a minor injury and was treated on scene. Humboldt Bay Fire will remain on scene throughout the day extinguishing hot spots and a damage estimate is unknown at this time. The cause of the fire is under investigation and Humboldt Bay Fire will release further information when it becomes available.