Ezekiel 33:5

He heard the sound of the trumpet and did not take warning ; his blood shall be upon himself. But if he had taken warning , he would have saved his life .

Since they heard the sound of the trumpet but did not heed the warning, their blood will be on their own head. If they had heeded the warning, they would have saved themselves.

He heard the sound of the trumpet, and took not warning; his blood shall be upon him. But he that taketh warning shall deliver his soul.