The Malbone Street wreck, also known as the Brighton Beach Line accident, was a rapid transit railroad accident that occurred on November 1, 1918, on the New York City Subway's BMT Brighton Line (now part of the BMT Franklin Avenue Line) in the community of Flatbush in Brooklyn, New York, United States. A speeding train derailed in the sharply curved tunnel beneath Willink Plaza, the intersection of Flatbush Avenue, Ocean Avenue, and Malbone Street (now known as Empire Boulevard). At least 93 people died, making it one of the deadliest train crashes in U.S. history, as well as the deadliest in the history of the New York City Subway.

The circumstances leading to the crash included a labor strike against the Brooklyn Rapid Transit Company (BRT). The BRT had tried to keep service running with non-striking personnel, and decided to use Antonio Edward Luciano, a crew dispatcher with no experience operating the line. Other factors in the crash included the serpentine layout of the track and the weight of the individual train cars.

In the aftermath of the crash, Luciano and BRT officials were placed on trial for manslaughter. Ultimately, all the defendants were acquitted or their indictments were dropped. The BRT gradually phased out wooden cars and additional train protection devices were installed. The two most heavily damaged train cars were scrapped. In 1923, the BRT became the Brooklyn–Manhattan Transit Corporation, having gone bankrupt due to the accident. The tunnel in which the wreck occurred remained in daily passenger operation for forty years. A memorial to the crash was installed in 2019.