A fire in September 1725 destroyed houses on the bridge's east side and damaged some on the west side; they were rebuilt. The last houses to be built on the bridge were designed by George Dance the Elder in 1745, but even these elegant buildings had begun to subside within a decade. In 1756, the London Bridge Act gave the City Corporation the power to purchase all the properties on the bridge so that they could be demolished and the bridge improved. While this work was underway, a temporary wooden bridge was constructed to the west of London Bridge. It opened in October 1757 but caught fire and collapsed in the following April. The old bridge was reopened until a new wooden construction could be completed a year later. To help improve navigation under the bridge, its two centre arches were replaced by a single wider span, the Great Arch, in 1759.