As if cued, a sudden BOOM caused her to cry out, to raise her hands to the headphones and her ears within them. A second BOOM followed quickly, and she worried her hearing might be permanently damaged. Shaking, she lowered the volume and looked to the zoomed screen of her iPhone. It was there. Something like a hoof upon the white wood. A deer on the bridge? It was near the head of the bridge, so that Brenda could see only its leg, its hoof. And its steps had nearly deafened her.