and the filbert street stairs, because of the rockfall that occurred, new stairs were built, and they were built in a manner that when rockfalls occur, that actually lift out the stairs and put them on the ground and allow the crane to get back there to access the rockfall. >> beyond that, the building that we see at the bottom of the rockfall was actually designed to allow barack to fall off and be compounded by the building -- actually designed to allow barack to fall off and be impounded by the building. >> that is the corner of sansome and green. every couple years, there is a rock fall that occurs behind that building. >> now we are on russian hill. this is the most beautiful location of exposed bedrock. across the street from the art institute on chestnut. >> that and tires sitting -- that entire setting, that is a beautiful setting, the deck and the panorama of the city. >> cannot be it. now we are on at leavenworth street, around the corner of chestnut or francisco. >> these walls are common throughout the city, and they were built as part of the stimulus package following the

on the half block section of columbus between union and filbert, and only one lane of traffic was closed at a time for this utility work. the construction of the retrieval shaft is scheduled to again 2013, and will be completed in approximately 10 months. the retrieval shaft excavation will require the closure of two lanes on columbus avenue. to minimize effects of construction we have employed a variety of measures including traffic control and daily street sweeping. the agency decided to move forward with the utility relocation of the proposed columbus street retrieval shaft to meet contractual and grant funding obligations. in the meantime, we've also reviewed four options. some of the residents and business owners in north beach expressed concern that the north beach retrieval shaft work if if carried out as planned would impact the neighborhood without providing benefits of an enhanced public transportation system. the community [speaker not understood] project team to evaluate options and the options evaluated includes included a number of criteria. and including the impediments to