Underground Exploration Begins for 48-Story High-rise at 1320 S. Michigan

A reader writes in regard to the proposed high-rise at 1320 S. Michigan:

Earlier this week construction vehicles from the company Strata appear to have started underground exploration of the lot. Spoke with the parking attendant, he says he expects to be out by the end of September.

As you may remember about a year ago, this rendering for a 48-story building came out:

(Hat tip:  NS!)