Yes it is terribly sad

However, tragedies can happen on both sides.
I used to live very close to the towpath of the Grand Union canal and regularly saw swans and had the pleasure of watching them make their nests, incubating their eggs and then venturing on to the water with their babies. On one occasion, the cob and pen and their offspring were travelling along the canal when for some reason one of the cygnets got separated from the rest and trapped in the lock. Mum and Dad tried to get the youngster out but couldn’t. Along came a guy with a springer which immediately went into the lock and caught the swan baby and killed it. The owner just calmly took the body and tossed it into a nearby field. My heart went out to the swan family as it had to witness the death of its young.
These tragedies can be so easily avoided just by keeping your dog on the lead.