why does my script take two lives instead of one when i die

Hi,i made a script in a 2d game that when i fall off a block my player collides with a box collider then looses a life and respawns but intead of taking one life it takes two i dont understand why

Maybe you have two colliders so the collision function is being called twice? Add a Debug.Log(this); to see how many times its being called and from where