Wrecking balls — a voyeuristic freebie, providing guilt-free observation of raw destruction. Today, big metal ball met concrete and steel when the 71-year-old Transbay Terminal in San Francisco got the ole treatment. Watch a video by KQED’s Mina Kim.A new terminal, the San Francisco Transbay Transit Center, is scheduled to open in 2017. Here’s a video overview on the proposed new terminal. For the nostalgically inclined, you can check out photos of the old terminal on Flickr.