Authorities in Japan say several people are known to have died in a highway tunnel where about 150 concrete panels fell from the roof.
The precise number of fatalities is unclear. Several vehicles are believed to have been buried in the tunnel 50 miles outside Tokyo, on the main highway linking Tokyo with central Japan.
Efforts to rescue survivors trapped inside the tunnel have been hindered by heavy smoke after one vehicle caught fire. Fears of a further collapse also prompted rescuers to suspend their work temporarily.
The Fire and Disaster Management Agency says five people were confirmed to have been in a car that burned inside the tunnel, and at least one other person was in a truck.
Executives for Central Japan Expressway Co. say the company is investigating why the concrete panels gave way. They say nothing was found amiss when the tunnel's roof was checked in September and October.
The 3-mile-long tunnel opened in 1977.