According to Asahi News, BBC News, and the blog Far East, a US transport helicopter crashed on Friday the 13th (!) at the Okinawa International University in Ginowan in Okinawa. Three crew members were injured (one seriously) in the accident. About half of the 48,000 US military personnel in Japan are stationed in Okinawa--a situation that probably won't change much in spite of the newly proposed cutbacks of previous overseas postings. The CH-53 helicopter hit one of the university buildings before crashing and catching fire (The BBC article says it "grazed" the building, but the pictures suggest a more serious accident.)
The recent crash has poured salt into old wounds as locals express their disgust after years of crimes (rapes in particular) by US servicemen. According to Far East, even 3 days after the crash, the U.S. military has refused the local Japanese police access to the crash under the despised "Status of Forces Agreement" (SOFA), which gives the US special rights in Japan. Paradise Factory likewise reports that the Japanese police have been posted to stop traffic only, and that only the U.S. has been allowed to investigate details of the accident.
Far East (a Japanese blog) has an excellent post on the crash. Both the original blog article and the comments are very illuminating. The Japanese sense of outrage at the U.S. handling of the incident has been, in my opinion, under-reported in the Western press.
See also: I love Okinawa and Paradise Factory (Japanese blogs).