Church of St Andrew Undershaft, St Mary Axe, City of London, 11 July 2012. Digital photograph by James O Davies (1966-). The 1894 London Building Act restricted the height of buildings until these regulations were relaxed in the 1950s and the boom in tall buildings began. The tower of the church of St Andrew Undershaft dates from the 15th century, and for centuries it dominated buildings in Leadenhall Street, particularly after the addition of corner pinnacles and a turret in 1883. Many buildings beyond the church were destroyed by fire in 1893, and replaced by the Baltic Mercantile & Shipping Exchange and other commercial buildings. The Baltic Exchange was badly damaged by an IRA bomb in 1992, and made way for the Swiss Re Building, popularly known as The Gherkin, which was completed in 2004.