'Human error' after US chopper window falls on Japan school

https://www.yahoo.com/news/human-error-us-chopper-window-falls-japan-school-085507527.html

The US military on Monday blamed human error after a window from one of its helicopters fell onto a school sports ground in Japan, sparking anger among local residents.

The military said it had conducted a thorough investigation into last Wednesday's accident and concluded that "the incident was caused by human error".

"The window in question is designed to be removed in order to assist pilot egress in an emergency situation. The appropriate procedures for ensuring the window was secured were not correctly followed," added the military in a statement.

It again apologised for what it called a "regrettable" accident.

There were no serious injuries from the window that landed at an elementary school near the Futenma marine airbase on Okinawa island.