Recently a blind woman in the US was saved from being hit by a speeding school bus by her guide dog. Some years ago I remember reading about how a guide dog had knocked his master down to protect him from a swinging crane. I was wondering if the woman would have been safe if she was just moving with her white cane. Certainly, a guide dog is not only a mobility support to the blind person but also an efficient companion who could be a dynamic assistant in times of need.