Gelitin

Okay.

The second is an Austrian collective at the time called Gelatin.

A year earlier in March of 2000, working out of a vacant space on the 91st floor, they removed a window, built a small wooden platform, and pushed it out through the opening, standing on it briefly while it was photographed from a chartered helicopter at dawn.

The entire thing lasted about 19 minutes before they pulled the platform back in and sealed the window.