of a central business district. The Williams Tower was the product of a unique era in Houston: energy companies were highly profitable entities and they sought impressive, monumental structures to broadcast their power. The Williams Waterwall is a multi-story sculptural fountain which sits at the south end of Williams Tower in Uptown. It and its surrounding park were built as an architectural amenity to the adjacent tower. Both the fountain and tower were designed by Pritzker Prize winning architect Philip Johnson. Construction of the complex was completed in 1983. The semi-circular fountain is tall and sits among 118 Texas Live Oak trees. Approximately of water flow over both sides of the wall every minute. The Uptown District is also home to other buildings designed by noted architects such as I. M. Pei and César Pelli among others also designed by Philip Johnson; Pelli designed the Four Oaks Place complex. Large-scale office construction in Uptown came to an end with the collapse of energy prices and the meltdown of Houston's economy in the mid-to-late 1980s. Uptown had 23.8 million square feet (2,210,000 m2) of office space in 2001, whereas Downtown Houston had about 40 million square feet (4,000,000 m2). In the late 1990s, there was a mini-boom of mid-rise residential tower construction, typically about 30 stories tall. Uptown has accumulated a large concentration of high-rise residential structures. Four Leaf Towers, a high-rise residential complex consisting of two 40-story buildings located on San Felipe Street was constructed in 1982. The towers were designed by architect César Pelli. Completed in 2004, Saint Martin's Episcopal Church (with spires and antennae reaching into the sky), designed by Jackson & Ryan Architects, was featured on the covers of three national magazines: Civil Engineering magazine (April 2005), Modern Steel Construction magazine (May 2005) and Structure magazine (December 2005). Government and infrastructure Local government Uptown Houston is a Tax Increment Reinvestment Zone (TIRZ), which is a self-imposed taxing entity created by property owners in economically challenged areas in order to fund improvements and encourage development within the zone. The area was designated as a TIRZ by city council. The Uptown District has used the funds for landscaping and mobility improvements as well as specialty street lamps, signage and stainless steel gateways and halos over major streets and intersections. Houston Fire Department operates Fire Station 28, a station in District 28, west of Uptown. Station 28 moved to a