ローム斜面崩壊実験事故慰霊碑

On a crisp November day in 1971, a tragedy unfolded at the Kawasak Rome Slope Failure Experiment Memorial in Tokyo. This seemingly ordinary park became the site of an unimaginable disaster during a slope failure experiment. The experiment, known as the “Kawasaki Rome Shamen Houkai Jikken,” was meant to study the mechanics of landslides. It was a collaborative effort, involving four government research agencies: the National Research Center for Disaster Prevention, the Public Works Research Institute, the Fire Research Institute, and the Geographical Survey Institute. They wanted to understand how landslides occur on the Kanto Loam Formation. Researchers sought to determine the rainfall threshold that triggers landslides on plateaus composed of this loam. This involved artificially inducing landslides by spraying water on a slope in Ikuta Ryokuchi Park. The slope was set at a 30-degree angle, with a planned collapse area extending 100 meters. Observers and reporters positioned themselves approximately 50 meters from the slope’s base, behind a one-meter high protective fence. Prior experiments had been conducted, with water sprayed on the slope for seven days. Now, before you stands the memorial. It stands as a somber reminder of the day when the experiment went horribly wrong. On November 11, after spraying 470 millimeters of water, the slope collapsed. The speed and scale were far greater than anticipated. The resulting mudslide overran the protective fence. This tragically buried 25 people. Fifteen lives were lost, including eleven researchers and four reporters. The incident was captured on film. Footage shows the earth giving way, engulfing people in its path. The disaster exposed several critical safety oversights. Warnings, evacuation plans, and communication with reporters were insufficient. The designated observation area was dangerously close to the slope, with the only escape route blocked by a pond. The subsequent investigation also revealed discrepancies in the pre-experiment soil analysis, which failed to adequately assess the risk. Two researchers faced charges of professional negligence resulting in death, but were ultimately acquitted sixteen years later. The court deemed the tragic outcome unforeseeable given the scientific knowledge at the time. The Kawasak Rome Slope Failure Experiment Memorial serves not only as a memorial to the victims. It also serves as a stark reminder of the importance of meticulous planning and comprehensive risk assessment in scientific endeavors.