Updated

A low cinderblock wall collapsed Friday at a school, injuring five boys, none seriously.

The boys, ages 11 to 14, had been sitting on the 4-foot-high wall when a section gave way. The wall served as a counter for a concession stand near Crooked Oak School's football field.

The youngsters had mostly cuts and scrapes, said Shannon Goodsell, school superintendent. They were treated at a hospital and released.

The wall fell while boys were involved in a physical education class, and nearby coaches immediately came to their aid.

Goodsell said structural engineers would investigate why the wall collapsed.

The Crooked Oak School (search) complex is in an industrial and working-class area of Oklahoma City and includes an elementary school, a middle school and a high school.