After two and half years of construction, the $1.2 billion Wilshire Grand in Downtown Los Angeles is now the city's tallest building. And according to project officials, the 1,100-ft tower is also the tallest structure west of the Mississippi River.

The milestone was reached on September 3 when workers used a crane to position the 294-ft, 9-inch steel spire in place and then cap it with a beacon. This was the latest achievement for the iconic building, which began with a record-breaking concrete mat pour in February 2014 that saw a three-day convoy of trucks shoot 24,000 cu-yds of concrete into the structure’s 20-ft-thick mat foundation.

The 73-story project, which has created an estimated 122,000 new jobs across the city, is currently about 85 percent finished and is scheduled to complete in 2017. Construction is being led by Turner Construction Company, Brandow & Johnston is the Structural Engineer of Record, and A.C. Martin was in charge of the design.

Chris Martin, CEO and president of A.C. Martin, said at the spire placing celebration that the public is finally getting a glimpse of a project that "will redefine what it means to work, live and stay in Downtown Los Angeles.”

Martin told me a couple years ago that this project is a "big deal because my grandfather did L.A. City Hall in the 1920s, and that is the only other building in the city that really has an architectural top. All the buildings in L.A. have flat, truncated tops, so this is going to stand out—and we want it to."

Martin, whose cousin David Martin is the lead designer on the new hotel, says the spire and the entire exterior skin of the tower will be filled with programmable LED lighting, which will be seen throughout the city, and used to “artistically to give character to the building in light."

The project, located on the site of the former Wilshire Grand hotel, which closed in 2011, is highlighted by a 900-room, luxury hotel above 400,000 sq ft of office space and more than 45,000 sq ft of retail, and below grade parking for 1,250 cars. Other significant features include the 70th floor sky lobby along with signature observatory, sky pool deck and restaurants.

Brandow & Johnston's website says the project is utilizing a unique lateral system. The building has a concrete core wall up to 4 ft in thickness with buckling restrained outrigger braces in the transverse direction at three elevations along the height of the structure. At two of the outrigger levels the structure has a perimeter belt truss to resist torsion and provide for vertical load redundancy.

For gravity loads the structure utilizes a concrete and metal deck floor framing with structural steel beams and girders. The perimeter building columns are composite steel box columns filled with structural concrete.