On Tuesday, a window out of a Marine Corps CH-53E Super Stallion fell from the skies above a Japanese elementary school.  One 10-year-old boy playing in the nearby sports field suffered minor injuries.

Many Japanese residents have grown increasingly frustrated with a slew of U.S. military incidents in their country, including aircraft failures and violent crimes involving American military personnel.  Just a week ago, another part from a U.S. military helicopter fell off in flight, this time landing on the roof of a pre-school.  There were no injuries reported in that incident.

“It’s outrageous this happened again,” Okinawa Gov. Takeshi Onaga told reporters.  “Despite repeated accidents, U.S. military officials would not lend their ears to our concerns.”

The metal frame and window, measuring approximately three-square feet and weighing around 17 pounds, fell from the Super Stallion at 10:09 a.m. on Tuesday.  Some 50-60 children were gathered in the field the component landed in, but only one child suffered minor injuries when hit by gravel kicked up by the impact of the window.  Immediately after the incident, the helicopter returned to Marine Corps Air Station Futenma, located about 2.3 kilometres (1.4 miles) from the school.

CH-53 window in the school field, courtesy of Twitter

“The safety of children should come first. It is unforgivable that it dropped in the middle of the playground,” Takeshi Onaga, said of the incident.

His sentiments were echoed by Japan’s chief cabinet secretary Yoshihide Suga, who said the incident “creates anxiety” among the Japanese populous and “should never happen.”

U.S. Forces, Japan immediately acknowledged the incident via press release, and stated that they are conducting an investigation “in close coordination with local authorities.”

“This is a regrettable incident and we apologize for any anxiety it has caused the community.” The statement went on to say.