The ceremonial ringing of the bell in memory of those who died in the line of duty is an age old tradition of the Fire Services that dates back over 150 years. The tradition reflects respect and honor to those who gave their lives to their duty. A distinctive bell ringing marks the end of an emergency and a return to quarters. In memory of all who died during the attacks on September 11, 2001 the bell is rung five times in series of fives (5 x 5 x 5 x 5 x 5). Multiplied out this equals 3,125, a number very close to the number of people who died as result of the attacks.