Complex sentence: The Amazon campus, designed by Seattle architecture firm NBBJ, was approved by the Seattle Department of Planning and Development in late 2012 and excavation on the 37-story Tower II began under the direction of Sellen Construction in 2014.
Split into simpler sentences: The Amazon campus, designed by Seattle architecture firm NBBJ, was approved by the Seattle Department of Planning and Development in late 2012. Excavation on the 37-story Tower II began under the direction of Sellen Construction in 2014.