The .kml start file can be downloaded directly into Google Earth by clicking on the Gasometer_1.kml file. The complete demo COLLADA files including the .kml start file can be downloaded as a .zip compressed folder for local browsing. Google Earth needs to be installed on your computer.
Note: The current version of Google Earth seems to have a problem loading large tiled COLLADA models. In order to avoid the problem and get the whole model loaded, please move slowly through the scene.