This song is 11 minutes long and divided into three sections:
The first part is joyful, with a string quartet playing as Lou Reed
tells of two people who meet for a sexual encounter. The tone changes in the second section, which begins with somebody (a landlord, perhaps) discovering the girl dead and telling the guy he needs to get rid of her. His advice: dump her on the street, where it will look like a hit and run.
In the third part, he ruminates on what just happened and tries, unsuccessfully, to make sense of it.