Liberty City Sawmills
Liberty City Sawmills is a company in Trenton, Portland, Liberty City in GTA III and GTA Liberty City Stories that makes timber, wood and furniture. The company also has branches outside Liberty City. Drilling can always be heard when on the rooftop or the level right below the rooftop.
A hidden package can also be found on the rooftop in GTA III. It is only accessible from the back by jumping onto a large vehicle and jumping the fence.