Things you might not know about the IDS

• The IDS Tower was the nation's 16th-tallest building when it opened in 1973.

•Architect Philip Johnson referred to the distinctive cuts in the tower's corners as "zogs."

• John Tappan founded Investors Syndicate (later Investors Diversified Services, then American Express Financial Advisers, now Ameriprise) in 1894 in the Lumber Exchange Building at 5th St. and Hennepin Av. S. in downtown Minneapolis, four blocks from the IDS Tower.

• The Crystal Court's rainfall-inspired fountain, added in 1998, is positioned where Johnson had originally planned a more elaborate bronze fountain, which was cut from the original plans.

• The center's eyesore of a heating and cooling plant (now the NRG Energy Center), two blocks to the east of the IDS, opened in 1972 at a cost of $13.5 million ($69 million in 2008 dollars).

• There was no formal dedication, in stark contrast to the Foshay Tower's dedication festivities 44 years earlier, which featured parades, speeches, dancing girls and John Philip Sousa conducting his newly commissioned work, "Foshay Tower Washington Memorial March." (Owner Wilbur Foshay's check to Sousa bounced.)

• By 1975, the center's tax assessment was roughly $45 million less than its final construction cost, and IDS was losing several million dollars a year in operating costs. "I am absolutely convinced that if the facts that are known today had been known before the first shovel was in the ground, the building would have never have gone up," H. Clifton Whiteman, IDS senior vice president for corporate finance, told the Minneapolis Star that year. The company eventually received a multimillion-dollar property-tax break.

• A pair of outdoor elevators, designed to whisk diners from the tower's lobby to a penthouse restaurant, were scrapped.

• Andy Warhol created a painting especially for the center's hotel, the Marquette Inn, that was reproduced for each of its 285 rooms.

• The center included a 400-seat movie theater on the concourse level below the Crystal Court. It opened to raves ("A small, glowing gem of a theater" said Minneapolis Star columnist Don Morrison) on Nov. 8, 1972, but to say that it didn't catch on with the moviegoing public is an understatement. Four years and an ownership change later, the theater screened its last film and the space was converted to a conference center.

• From its opening on Nov. 22, 1972, the tower's 51st-floor observation gallery -- 717 feet above the sidewalk -- was a popular attraction. By March 1975, the panoramic views had drawn 1 million visitors. It closed on Dec. 31, 1983, and the space was converted to more lucrative offices.