In Photos: Object believed from US military helicopter falls onto Okinawa elementary school

The object thought to have fallen from a U.S. military helicopter is circled in red, center, in Ginowan, Okinawa Prefecture, on Dec. 13, 2017. (Photo courtesy of TBS Television via Ryukyu Broadcasting Corp.)

Okinawa Prefectural Police investigators examine a window frame that fell from a U.S. military helicopter, at the Futenma No. 2 Elementary School in Ginowan, Okinawa Prefecture, on Dec. 13, 2017. (Photo courtesy of the Ginowan Municipal Government)

Chaos ensues as the press and city assembly members gather on the grounds of Futenma No. 2 Elementary School after an object allegedly fell from a U.S. military helicopter, in Ginowan, Okinawa Prefecture, on Dec. 13, 2017. (Mainichi)

Okinawa Gov. Takeshi Onaga is seen after hearing about the object that allegedly fell from a U.S. military helicopter onto Futenma No. 2 Elementary School, in Ginowan, Okinawa Prefecture, on Dec. 13, 2017. (Mainichi)

The U.S. military helicopters from which something resembling a window fell onto an elementary school are shown leaving Marine Corps Air Station Futenma just before the incident, in Ginowan, Okinawa Prefecture, on Dec. 13, 2017. (Photo courtesy of TBS Television via Ryukyu Broadcasting Corp.)

U.S. military helicopters return to Marine Corps Air Station Futenma, after which the fallen object was confirmed, in Ginowan, Okinawa Prefecture, on Dec. 13, 2017. (Photo courtesy of TBS Television via Ryukyu Broadcasting Corp.)

An object, center, appears to fall from a U.S. military helicopter in Ginowan, Okinawa Prefecture, on Dec. 13, 2017. (Photo courtesy of TBS Television via Ryukyu Broadcasting Corp.)

The elementary school in Ginowan, Okinawa Prefecture, where the object apparently fell from a U.S. military helicopter is seen in the foreground of this photo taken from a Mainichi Shimbun aircraft. In the background is U.S. Marine Corps Air Station Futenma. (Mainichi)