Here's an excerpt from the art league press release, written before the project started:
"Havel and Ruck will create a large funnel-like vortex beginning from the west wall adjacent to Montrose Blvd. The exterior skin of the houses will be peeled off and used to create the narrowing spiral as it progresses eastward through the small central hallway connecting the two buildings and exiting through a small hole into an adjacent courtyard."
If you want to view the installation I think you're out of luck, having read that it's been demolished. Hopefully these pictures are a small consolation.