In December 1994 a $44 million seismic retrofit project began on the I-8/I-805 Interchange in San Diego. Two years later it was revealed that SGS Industrial Services, the contractor hired by Mejia Steel Welding to inspect the welding work done by Mejia, had improperly certified welds that were defective. The problem was first noticed by a state-employed inspector from CA Department of Transportation, when the state investigated fully they discovered that 73% of the 15,000 welds certified by SGS were defective. Had the problem gone undetected, the ability of the over-crossings to withstand a major earthquake would be vastly decreased, putting public safety at risk. Overall it cost $5 million to redo the welds and caused extensive delays to project completion.