The Maltese Cross is your symbol of protection. It means that the firefighter who wears this cross is willing to lay down his life for you just as the crusaders sacrificed their lives for their fellow man so many years ago.
The first American (volunteer) fire department company is often credited to Ben Franklin, around 1736, in Philadelphia. This started as a "club" or co-op, to protect each other's homes in the event of a fire.