Here is a quick video of how to use a piece of webbing to assist a firefighter out of a basement window. Understand, that depending on the height of the basement, the length of webbing needed may need to be longer. A 30 foot piece of webbing tied in a loop will work for most situations. The reason the loop is used is so if the webbing slips, it wont completely slip out of your hands if your one of the firefighters pulling on the outside.
Thanks for reading and watching and train hard.