The Sasago Tunnel (笹子トンネル, Sasago Tonneru) is a twin-bore motorway tunnel on the Chūō Expressway located on the border of the cities of Kōshū and Ōtsuki in Yamanashi Prefecture, Japan.

[4] At approximately 8 am on December 2, 2012, nearly 150 concrete ceiling panels inside the Tokyo-bound Sasago Tunnel collapsed, crushing three vehicles, including a van, carrying six persons, that caught fire.

[4][7] The caved-in point was 2 kilometres (1.2 mi) from the Tokyo-side exit and spanned a length of 50 to 60 metres (160 to 200 ft).

[8] Nine people died and two were injured, making it the deadliest roadway accident in Japanese history.

The tunnel was closed for a period of 27 days for repairs and removal of ceiling panels, before the south tube reopened on December 29.