The mystery began Wednesday morning when a steel pipe that had been underground during construction suddenly protruded in a busy area of Osaka, Japan, according to local authorities. The pipe rose more than 10 meters out of the site and at one point reached about 13 meters above ground, nearly reaching an elevated road, officials said. No witnesses saw the pipe rise, and it happened overnight in the stretch of work that had been largely out of public view.
Local officials said the discovery baffled residents and workers passing nearby. A pedestrian who saw broken pieces of asphalt falling from the pipe reported the problem to police early Wednesday, prompting a traffic congestion in the area. An office worker who passed the site told NHK public television he could not understand how the pipe could have risen, while another man working nearby said he initially wondered whether a new road support had been built overnight.
The Osaka construction department said the pipe was about 3.5 meters in diameter and at one point stood roughly 13 meters tall. Officials said the pipe’s unexpected elevation occurred at a sewer construction site where workers were connecting an existing sewer line with a channel intended to hold excess rainwater to prevent flooding.
Officials said the pipe was being used as a retaining structure to keep surrounding soil from collapsing during the operation. They said workers had drained water from the pipe earlier, and that the empty apparatus may have floated after the water was removed, allowing it to rise.
By Thursday, the pipe had been lowered back to several feet above the ground. Firefighters cut a hole on the side of the pipe and injected water to push it back down, according to local accounts.
City officials said they plan to cut the last 1.6 meters of the pipe that would remain visible. They added that the operation would require closing the road for several more days as workers handle the remaining section safely.