The leaning tower… Experts say they can straighten up San Francisco’s tilting Millennium Tower. The “Chronicle” reports a couple of engineering firms say drilling 50 to 100 new clusters of steel pipes into bedrock would stabilize and straighten the 58-story luxury condo building. The high-rise at Mission and Fremont streets has settled 17 inches since construction started in 2005, including an inch in the past seven months. The engineering firms estimate stabilizing and straightening the tower would cost 100-million to 150-million dollars.