Near the end of the movie when batman is pursuing the joker up the church stairs, the joker sprays acid from his flower to make the bell fall, which blocks the door for the police. When batman reaches the top and fights the ninja, you can clearly see that the bell is back again. Infact he uses the bell to defeat the ninja. Either that church has two bells or they forgot that it had fallen earlier. I've never heard of a church with two bells.