After years of delays, that sunken pit at Tenth and Market Streets finally saw some action last night. Construction crews working on the forthcoming 37-story, 754-unit apartment complex adjacent to the new Twitter HQ used five pumps and 11 hours to pour over 660 truckloads of concrete for the tower's foundation.

According to Handel Architects, who are now in charge of the project, the building is meant to "infuse a young urban vibe into the neighborhood" with "modern and technology-driven" design, so expect that stretch of Mid-Market to just explode in to a vibrant neighborhood any day now.

In the meantime, a rendering of the finished product:

Previously: Central Market Watch: A Look At Developments Coming to 10th and Market

Credit: Handel Architects