The Union Station tower groundbreaking took place Friday morning, and Chicago and BMO Harris Bank officials were expected to attend.

Plans for the 50-story tower next to Union Station were announced earlier this year, and now work on the building is underway.

Steel erector Chicago Steel put the first 80-ksi members in place in late October, working for general contractor Clark Construction.

MKA specifies new ArcelorMittal steel products to create larger upper-level spaces in the 51-story tower and deal with site issues near Chicago Union Station.