Wednesday was a scary day for a cluster of bird lovers who have gathered downtown to watch Salt Lake City's famous peregrine falcon babies fly.

For nearly a week, Bob Walters has been staked out with binoculars and 20 years experience on the corner of 100 South and Regent Street. All day he watches the skies and the white, weathered box just below the First Security sign, his amplified lenses trained on the fuzzy brown dots 15 stories up. He's weathered 90-degree days and thunderstorms waiting for three fledgling falcons to take air.

Tuesday morning, about 10:25 a.m., one did.

The 6-week-old falcon tottered to the edge of the nesting box, leaned out, lifted her wings, then flew straight east, landing on the west wall of the Questar building directly across the block.

Walters, the "watchable wildlife" program coordinator for the state Division of Wildlife Resources, and a half-dozen friends scrambled to figure out where the bird landed. Someone watching from the Beneficial Life Tower at State and South Temple called to say she'd seen the bird, which was fine and walking around the roof.

Walters and his friends watched until 9:30 p.m. while the small bird of prey checked out the microwave tower high above the corner of 100 South and State Street.

But early Wednesday, Walters found a wounded bird, stunned, on the sidewalk when he reported to his viewing spot at 6 a.m.

He now believes the falcon is female. She had crashed into a window on the south side of 100 South.

"She was banged up, kind of defensive, and her eyes were open," Walter said. "Her wings were a little frayed, and she'd lost some feathers."

He's seen enough of these kinds of cases in 20 years to know babies stunned like this either "die or come out of it."

He quickly handed off the fledgling to a bird rehabilitation expert, then stood around like a worried father for several hours. Other falcon watchers studied the smudge on the glass where the bird clearly hit. They all surmised the falcon flew down sometime in the evening or morning and — maybe scared by a car — flew into the window.

"It's kind of a bummer," Walters said. "But we can't sit around and pout all day. Life and death — it's all part of the program."

Word came about noon: The bird should be fine. No broken wings, no permanent damage.

She was staying overnight for observation but would be reintroduced to her falcon family in the next day or so.

In the past, humans have helped reintroduce injured fledglings with an elevator ride, Walters said.