Complex sentence: The site was once proposed for a 31-story mixed-use high-rise, known as the Seventh at Westlake Tower, that was canceled in 2012 after being on hold for four years.
Split into simpler sentences: The site was once proposed for a 31-story mixed-use high-rise, known as the Seventh at Westlake Tower. However, the plans were canceled in 2012 after being on hold for four years.