Since the departure of the Sonics in 2008, the city has been working to bring back the National Basketball Association and attract a National Hockey League expansion team. Los Angeles developer Oak View Group recently released renderings of the privately financed $600-million renovation of KeyArena, scheduled to be completed in 2020. The arena currently hosts WNBA team Seattle Storm. The project will preserve the structure’s Paul Thiry-designed roof while adding a 360-ft-long glass atrium and a pedestrian plaza in the southeast corner. The design includes a 17,000-seat hockey arena. The Seattle NHL group quickly met its goal to sell 10,000 season ticket deposits after tickets went on sale March 1. OVG has also agreed to provide an additional $40 million for transportation mitigation around the 74-acre Seattle Center.