Police raid Japan tunnel operator offices after collapse The transport ministry, meanwhile, has ordered inspections of 49 other highway and road tunnels of similar construction around the mountainous country. An estimated 270 concrete slabs suspended from the arched roof of the tunnel, each weighing 1.4 metric tons (1.54 short tons), fell over a stretch of about 110 metres (120 yards), Noguchi said. Two people suffered injuries in the collapse. The operator was exploring the possibility that bolts holding a metal piece suspending the panels above the road had weakened with age, he said. The panels, measuring about 5 metres (16 feet) by 1.2 metres (4 feet), and 8 centimetres (3 inches) thick, were installed when the 4.7-kilometre-long (3-mile-long) tunnel was constructed in 1977. Crews had to stop recovery work on Monday in the tunnel about 80 kilometres (50 miles) west of Tokyo because the roof needed to be reinforced to prevent more collapses, said Jun Goto, an official at the Fire and Disaster Management Agency. By Tuesday, crews were removing the concrete slabs from the tunnel, said Goto, who added that authorities do not expect to find any more victims inside.