material is as much as a tic-tac and strong as steel, but can cause problems if someone is exposed. >>> walnut creek is warning people not to be alarmed if they hear gunshots and screaming coming from the school. it will be a part of the training exercise at walnut creek inter median. they are telling people ahead of time so they don't assume the worse tomorrow. >>> and a safety project could be delayed at sfo. the four runways will be closed through september. the airport is pouring crushable concrete to prevent planes from over shooting the runways. sfo says a summer closure is the fastest option for finishing the federally mandated project. >>> this is the time of year when students across the bay area are celebrating prom. the right of passage was enjoyed by students of all ages. their school is different than most others. but tonight they have to be like other kids. abc7 news anchor ama dates takes us to the prom. >> boys and girls. step up to the school prom at