A massive sinkhole that swallowed a truck in a city just north of Tokyo earlier this year has triggered a sweeping government investigation into Japan’s ageing sewer network, uncovering 72km of pipes in “critical condition” and raising alarm over a broader crisis of neglected infrastructure.The Ministry of Land, Infrastructure, Transport and Tourism ordered the investigation after the deadly accident in the city of Yashio, in Saitama prefecture, on January 28. Security cameras caught the moment...