A fire burning at a cardboard manufacturing plant in Santa Clara this morning has been knocked down. Firefighters are evaluating their progress to see what their next steps will be. They are also checking out some liquid propane tanks to make sure they weren't damaged. The fire call came just after 1:30 a.m. Flames threatened power poles and prompted the evacuation of the California Paperboard Corporation. The good news, the plant manager confirms all employees are safe and have been accounted for. The factory is on the 500 block of Matthew Street. It is burning in cardboard bales stacked 15 feet high in the storage area on the outside of the building. Overhead high voltage lines made it extra dangerous for the first firefighters on scene.