Preliminary work to rebuild the I-35W bridge in downtown Minneapolis is underway this week, but it will be a long time before Minnesotans get over the tragic collapse that occurred Aug. 1. Most of us only saw the photographs and the videos, and heard the voices on the radio. But there are also the approximately 180 people who were actually on the bridge when it crumbled into the Mississippi River. Thirteen of them died and dozens were injured. Midday features MPR's Cathy Wurzer's interviews with two of the survivors. Lindsey Petterson and Erica Gwillim survived the collapse of the 35W bridge on Aug. 1 but were both injured in the accident.