The incident took place on Thursday afternoon. Library picture: US Department of Defense.
An investigation is underway after a box of ammunition fell from a United States military helicopter and into the roof of a school.
No injuries were reported following the incident at Parkland Elementary School in El Paso in the state of Texas.
The commander of 1st Armored Division Combat Aviation Brigade, based around ten miles away from the school at Fort Bliss, has issued an apology.
"I'm extremely sorry for any damage done to the neighboring elementary school, and I am grateful that no one was injured," he said in a statement.
The box caused a power cut in the school building and damaged the roof.
The ammo has now been returned to military police at Fort Bliss.