That Sinking Feeling

We  were walking a somewhat unfamiliar trail. Most of the trail wound through woods adjacent to a lake, but part of the trail became a sidewalk and diverged through a townhouse community before continuing on. As the walk was fairly long, Gregg and I had been passing the leash back and forth between us, but at the moment, I was steering. As usual, Ray was leading.
Seeing a slight gap between the left edge of the sidewalk and the abutting grass that a blind dog could step into a find awkward, I warned Ray with a "careful" and pulled his leash a bit to the right.
I was too late. Ray's back paw hit the edge of the sidewalk and slid off into the gap. I watched stunned as his entire back leg disappeared.
Gregg ran to the dog and hauled Ray's back end up out of a chasm. What had looked like a small gap from the sidewalk was really an area of erosion around a drain pipe that traversed under the sidewalk.
"Oh my gosh, Ray, are you ok?" I asked the dog.
Ray took a few steps then stood and shook himself all over, shaking off the experience.
"That was a huge hole," I said to the dog, "You're lucky you didn't get hurt!"
Ray snorted indignantly and started off down the sidewalk again.
"That was really scary," I said to Gregg and Ray.
"It was," agreed Gregg.
Ray yawned. Obviously, all in a day's work for a blind hound.