Fire investigators are searching for a cause to Sunday's fire at Bernd Moving Systems at North 18 Avenue and Jerome in Yakima.  The fire was first reported at about 9 Sunday morning and burned for several hours before firefighters had the 4 alarm blaze under control. Today they'll be inside the building looking for clues as to what started the fire that heavily damaged a large warehouse that was full of household items. Firefighters fought high heat and a difficult and labor intensive challenge to control and extinguish this fire. All Fire Departments from the Nile to Toppenish assisted Yakima Firefighters with this fire. The Investigation started late Sunday and will continue early this morning. The damage is a rough estimate at $800,000 to 1.5 million dollars due to the unknown value of the contents of the building. About 100 firefighters responded and worked to douse the flames. No injuries were reported.