Galvanic corrosion is a process that degrades metals electrochemically. This corrosion occurs when two dissimilar metals are located in contact with each other in the presence of an electrolyte, such as salt water, forming a galvanic cell.
But the memories of that tragic day 25 years ago are still vivid to many in Edmond. On Aug. 20, 1986, gunman Patrick Henry Sherrill shot and killed 14 co-workers, wounded six and then took his own life inside the post office where he worked.
Below is a timeline of mass shootings in the US since the Columbine High massacre: December 11, 2012. On Tuesday, 22-year-old Jacob Tyler Roberts killed 2 people and himself with a stolen rifle in Clackamas Town Center, Oregon. His motive is unknown.