A majority of pipeline failures are caused by external corrosion. Failures in pipelines that carry oil result in oil spills that cause widespread environmental damage and economic losses for the oil companies, pipeline operators, and communities through which pipelines pass. Failures in pipelines that carry natural gas can cause far more damage. In extreme cases, thinning of the pipeline wall from corrosion can cause the pipeline to explode. A critical part of keeping our pipeline infrastructure safe is frequent and accurate inspection.