TOKYO — Japan has ordered a nationwide inspection of 49 tunnels after the collapse of a highway tunnel near Mt. Fuji killed nine people and crushed cars with almost 400 tons of concrete in the nation’s worst tunnel disaster in 16 years.

The Ministry of Transport ordered the inspections to be conducted by Dec. 12, according to a statement on the ministry’s website. About 270 concrete slabs, each weighing 1.4 tons, fell from the ceiling of the Sasago tunnel on the Chuo expressway about 50 miles west of Tokyo early Sunday morning.