FBI closes probe with no charges from allegations that Kiewit unit performed faulty construction of California highway bridgeWORLD-HERALD The FBI has closed its eight-month investigation into allegations that a joint venture led by Peter Kiewit Sons' Inc. produced hundreds of faulty welds in a $1.5 billion California bridge. "There was insufficient evidence that there were faulty welds and that they would compromise the integrity of the bridge," said LaRae Quy, FBI spokeswoman for Northern California. Criminal charges would have required proof of criminal intent and evidence that the welds were inferior. Most of the evidence - thousands of welds sealed in tons of concrete - is not accessible without tearing the bridge apart. Several independent investigations remain open, including those by California Attorney General Bill Lockyer and the Federal Highway Administration. Officials at the venture led by Omaha-based Kiewit, known as the KFM Joint Venture, declined to comment, referring questions to the bridge owner, CalTrans. Officials there did not return calls. In April, a number of welders claimed that Kiewit officials forced them to rush construction and cover up faulty work on the Bay Bridge "Skyway" project. In May, independent tests of two welds showed that the workmanship met or exceeded design specifications.