Why choose Koorsen? As one of the largest companies of our kind in the U.S., there happen to be a lot of good reasons to choose Koorsen. Here are a few that we're particularly proud of: Stability Koorsen Fire & Security has been in business since 1946. With over 60 years in the fire and security industry, Koorsen has the foundation and stability to deliver the fire and security protection products and services that you and your company demand and deserve. Family Owned Koorsen Fire & Security is a family owned and managed company. Our ownership takes an active role in the management of the company which makes you the beneficiary of quick and efficient local decision making by Koorsen personnel. Security Koorsen is the largest family owned loss protection company of it's kind.