Just an example I threw together using samples from the KML
documentation:
<?xml version="1.0" encoding="utf-8"?>
<kml xmlns="
http://earth.google.com/kml/2.2">
<Document>
<name>SF Marina Harbor Master</name>
<visibility>0</visibility>
<Style id="style1">
<IconStyle>
<Icon></Icon>
</IconStyle>
<LabelStyle>
<scale>1.1</scale>
</LabelStyle>
<LineStyle>
<color>7f0000ff</color>
<width>4</width>
</LineStyle>
</Style>
<Placemark>
<name>This is the Name of the Line</name>
<styleUrl>#style1</styleUrl>
<MultiGeometry>
<Point>
<coordinates>-122.442712,37.806649,0</coordinates>
</Point>
<LineString>
<!-- north wall -->
<coordinates>-122.4425587930444,37.80666418607323,0
-122.4428379594768,37.80663578323093,0</coordinates>
</LineString>
<LineString>
<!-- south wall -->
<coordinates>-122.4425509770566,37.80662588061205,0
-122.4428340530617,37.8065999493009,0</coordinates>
</LineString>
</MultiGeometry>
</Placemark>
</Document>
</kml>