Gillig Corporation, formerly Gillig Bros.,'s a manufacturer of heavy-duty low floor transit buses located in Hayward, CA. Prior to 1993, Gillig had also been a manufacturer of school buses. History In 1890, Jacob Gillig opened a carriage and wagon shop in San Francisco, CA, and was joined by his son Leo in 1896. The original shop was destroyed in the 1906 San Francisco earthquake, but reopened as the Leo Gillig Automobile Works manufacturing automobile, hearse, truck, and bus bodies. In 1920, L… (More on Gillig)