According to the information from the train driver, two persons are going to that area to search for it.
After a long time of searching, they find the mother dog lying near the railway track and they realize she is no more. The mother dog is gone.
Two puppies from six are lying slightly close to their mother. So they can easily find them. And also get all six puppies.
The above video is the story of the rescue of six poor puppies on the train track when their mother is no more.