Construction on what is believed to be the world’s fourth longest tunnel through hard rock came to a standstill this month when a crater 20m deep, and 70m in diameter opened up above the 22.2km long Iiyama rail tunnel in Japan, injuring three workers.
Newspaper reports said that two cave-ins occurred on the morning of 11 September, which caused earth to flow into the tunnel. The three workers were buried by a third cave-in, as they were piling up sand bags to prevent further inflows.
More details in October’s T&TI
