Was it necessary to kill children?

Have you ever heard the children’s evacuation ( gakudo-Sokai)?

The children had to move to safer places when the war was severe.

The ship which was carrying the children from Okinawa was attacked by a torpedo 

and about 1,500 children were killed.

Do you think that it was necessary to kill children?

To tell the truth, I had a similar experience when I evacuated from Tokyo to my home town.