One Canada Square was completed. It is expected to become the third tallest building in the United Kingdom in 2019 upon completion of 22 Bishopsgate. One Canada Square never achieved the title as tallest skyscraper in the European Union because in accordance to the CTBUH method, a building has to be "completed" before its receives its title, with Messeturm in Frankfurt being completed in 1990. On 15 November 1992, the Provisional Irish Republican Army attempted to place a large improvised explosive device near the tower. The IRA had already worked out that to cause maximum damage, the bomb had to be placed under
Centre Square (building) works of contemporary art. Until the company left in the mid-1980s, Arco Chemical Co., whose headquarters was in Centre Square, had a large collection of contemporary art displayed throughout the complex. Philadelphia has a percent for art program, which requires that a percentage of construction costs be allocated for art. A fan and collector of contemporary art, developer Jack Wolgin had three pieces commissioned to fulfill the ordinance. The most famous piece is Claes Oldenburg's Cor-Ten and stainless steel sculpture, "Clothespin". Located atop the subway entrance in the plaza in front of the building, Centre Square is best known because