Traditionally , the number 5 in the fire service was used to say the call was over and the company has returned to quarters. While resetting the "Pull Box", the Chief would ring out the number 5, or a combination of 5's, like 5-5-5, to notify all other companies that the call was over.
The 911 system ended the pull box system, however, steeped in tradition, the fire service kept the same 5 code in place. For most departments it signifies that a firefighter has answered his last alarm, and is now at rest.
The mission of 5-5-5 Firefighter Fitness is to reduce Line of Duty Deaths related to cardiac disease through fitness.