Complex sentence: In a city that host 6 of the 40 tallest buildings in the world and 10 of the top 100, with more under construction, this is the tallest building on Chicago's in the southern half of the city.
Split into simpler sentences: In a city that host 6 of the 40 tallest buildings in the world and 10 of the top 100, with more under construction. This is the tallest building on Chicago's in the southern half of the city.