Riverside’s emergency management program began after the city’s incorporation with the Civil Defense act of 1951 and Chapter 44 of the Missouri Revised State Statutes. Civil Defense has evolved to meet the ever changing complexities of the four phases of response to what is known today as Emergency Management. Homeland Security evolved after the September 11, 2001 attack on the United States where the President determined that not only should emergency managers prepare for what is known as “all hazards” preparedness to include domestic terrorism preparedness.