The Pui Tak Center, formerly known as the On Leong Merchants Association Building, is a building located in Chicago's Chinatown. Designed by architects Christian S. Michaelsen and Sigurd A. Rognstad, the building was built for the On Leong Merchants Association and opened in 1928. The Association used it as an immigrant assistance center, and the building was informally referred to as Chinatown's "city hall". In 1988, the FBI and Chicago Police raided the building as part of a racketeering investigation. The US federal government seized the building that same year. The building was purchased by the Chinese Christian Union Church (CCUC) for $1.4 million and renamed the Pui Tak Center in 1993. That same year, the On Leong Merchants Association Building was designated a Chicago landmark by the Commission on Chicago Landmarks. The CCUC spent $1 million raised from community donations to renovate and update the building's neglected interior. The newly-named Pai Tak Center now hosts various religious, community, and educational programs, such as English-as-a-Second-Language courses (ESL). In 2007, the Pui Tak Center won a $100,000 grant from the Partners in Preservation, a program sponsored by American Express and the National Trust for Historic Preservation. In preparation for the restoration work, the structural and architectural engineering firm Wiss, Janney, Elstner Associates completed an evaluation of the building's eastern and southern facades, focusing on its terra cotta portions. Restoration work began in spring 2009 and was completed in early 2010. Fully restoring the building's exterior terra cotta pieces and clay roof tiles is the first step in a long-range $2 million repair plan.