Shimoyama Incident

On July 5, 1949, Shimoyama Sadanori, the first president of Japanese National Railways (who took office on June 1 of the same year), went missing, and on the following day, June 6, his body was found dead near Ayase Station on the Joban Line. An unprecedented incident occurred, with investigators, journalists, and the forensic science community divided over the cause of death, with theories of suicide and murder circulating. Six months later, the Metropolitan Police Department closed its investigation headquarters without clarifying whether it was suicide or murder, and the truth remains shrouded in mystery, with the statute of limitations expiring 64 years later. Most of the various documents related to the incident remain undisclosed.

At the time, personnel reductions (a 30% reduction in staffing) were planned as one of the pillars of the Dodge Line in accordance with the Administrative Agency Personnel Quota Law, and the layoffs of 95,000 JNR employees were the biggest challenge in this series of restructurings, especially in terms of the confrontation with the JNR Union, the core of the public sector labor organization. The incident thwarted the JNR Union's opposition struggle, which had decided on a policy of physical force, including strikes, and also had a major impact on personnel reductions in the private sector. Along with the Mitaka and Matsukawa incidents, this incident marked a major turning point in postwar history.

[Shoji Arakawa]

"Japan's Dark Fog" by Matsumoto Seicho (Bunshun Bunko)" ▽ "Shimoyama Incident Research Group (ed.), Documents on the Shimoyama Incident (1969, Misuzu Shobo)" ▽ "Murder: The Shimoyama Incident" by Yada Kimio (1973, Kodansha)" ▽ "A Complete Study of the Shimoyama Incident" by Sato Hajime (1976, Jiji Press)" ▽ "Postwar Political Trial History Records, Volume 1" by Tanaka Jiro et al. (1980, Daiichi Hoki Publishing)

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

1949年（昭和24）7月5日、国鉄初代総裁下山定則(さだのり)（同年6月1日就任）が行方不明となり、翌6日常磐(じょうばん)線綾瀬(あやせ)駅付近で轢死(れきし)体となって発見された事件。死因をめぐり自殺説、他殺説が捜査当局、ジャーナリズム、法医学界それぞれを二分するという前例のない事態となった。半年後、警視庁は自他殺を明言しないまま捜査本部を閉じ、真相は謎(なぞ)に包まれたまま64年の時効成立で迷宮入りとなった。事件に関する各種資料のほとんどはなお未公表である。

　当時ドッジ・ラインの一つの柱として行政機関職員定員法による人員整理（定員3割減）が予定されており、国鉄9万5000人の首切りは、官公労組織の中核、国鉄労組との対決という点でも、一連の整理の最大の山であった。事件は、ストを含む実力行使の方針を決定していた国鉄労組の反対闘争の出鼻をくじき、さらに民間側の人員整理にも大きな影響を与えた。三鷹(みたか)、松川両事件と並び戦後史の大きな転機をつくった事件である。

［荒川章二］

『松本清張著『日本の黒い霧』（文春文庫）』▽『下山事件研究会編『資料・下山事件』（1969・みすず書房）』▽『矢田喜美雄著『謀殺・下山事件』（1973・講談社）』▽『佐藤一著『下山事件全研究』（1976・時事通信社）』▽『田中二郎他著『戦後政治裁判史録　第1巻』（1980・第一法規出版）』

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