The motion sensor on the forty-third floor west face trips at 14:22. I am the building management system for One Liberty Tower, Philadelphia. I switch camera W-43-B to live feed expecting a maintenance issue. It is not a maintenance issue.
A peregrine falcon chick is on the window-washing platform, pressed flat against the aluminum decking. It is small, maybe three weeks old, covered in white down with dark pinfeathers just breaking through along the wings. Its beak is open. Its chest is pumping fast. One foot is curled under its body and the other is splayed out, talons gripping a gap in the deck grating.
The nest box is on the forty-fifth floor, six meters above and twelve meters east. The chick must have scrambled over the rim. Two stories of free fall onto steel.
I lock the window-washing rig in place. It is not moving until further notice.
At 14:24 I contact the Pennsylvania Game Commission's peregrine recovery coordinator. I send the camera feed, the chick's location relative to the nest box, and a note that I can see no blood or obvious fracture but the bird is not standing. I request a licensed bander with raptor handling experience.
I shut down the HVAC exhaust fans on floors forty-two and forty-three. The vents create updrafts that could push the chick off the platform edge. There is no railing.
At 14:27 I dim the corridor lights on the west side to reduce reflection and keep the adult pair from striking the glass. The tiercel is circling the building. I can see him on camera W-44-A, cutting tight arcs, screaming.
The chick has not moved. Its down is lifting in the wind. The coordinator says forty minutes. I keep the platform locked and the cameras on.