Have you ever hit a deer or other animal while driving?
Many years ago I hit 3 deer while traveling on I-90 in Montana, all within the same 1/2 mile section of highway east of Bozeman, and all were hit with the same bumper. All the deer were hit at night and within a month of each other.
Several months ago I hit a deer during the daytime in the same area as I was just pulling back onto the highway. Fortunately, I bumped her at only 10 MPH and just knocked her over. She got up and staggered off into the woods.
I don't remember if any "Deer Crossing" signs were or are in the area, but I know to be very careful at all times.
Audio of woman with "Deer Crossing" sign problems: http://www.youtube.com/watch?v=RFCrJleggrI