On August 16, 2008, construction crews made the last major concrete pour to top off the Trump tower's concrete core, which was commemorated with an unofficial ceremony. To celebrate the milestone, a yellow tower crane raised a bucket full of concrete and an American flag to the rooftop of the skyscraper. Another ceremony occurred on August 19, when construction supervisors, structural engineers and company representatives from McHugh Construction made a minor concrete pour at the top of the Trump tower. Although Donald Trump was absent from both of these ceremonies, he, Donald Jr., Ivanka and Eric Trump attended the topping off party on September 24, 2008. Original plans called for the windows to be completed and the spire erected in October 2008. However, the spire installation was delayed through high winds in December 2008, and was finally completed on January 3, 2009. Kamin's critical opinion is that the spire is not aesthetically complementary.