Complex sentence: The first air attack against the "white buses" happened on April 18 when the Danish camp at Friedrichsruh was strafed by Allied fighter planes, four drivers and a nurse were slightly wounded, ten vehicles were destroyed.
Split into simpler sentences: The first air attack against the "white buses" happened on April 18 when the Danish camp at Friedrichsruh was strafed by Allied fighter planes. Four drivers and a nurse were slightly wounded, ten vehicles were destroyed.