Why does my FPSController destroy when I collide?

When my player collides with the r_pickup it destroys the fps controller, and i have no idea why. Sorry if its a easy fix, still a beginner :).

BTW it also does this when i use OnCollisionEnter()

using UnityEngine;

public class AimAnim : MonoBehaviour {

 public static AimAnim aimAnimInstance;

 public AudioClip pickSound;

 bool isPickedUp = false;
 bool IsAiming = false;
 bool hasAmmo = true;
 bool canReload = false;
 bool isReloading = false;
 bool isDead = false;


 public AudioClip shootSound;

 public GameObject bullet;
 public GameObject spawnLocation;

 public int Health = 100;

 public int Ammo = 1; //This is the ammo in a single clip
 public int MaxAmmo = 3; //this variable will be adjusted for each gun ammount of ammo in each clip all together
 public float reloadAnimTime; //The actual animation time for each aim for a gun will be the float number
 public float reloadTime; //This number is the same as reloadanimtime but its there so you can set animtime back to its original numb

 void Awake () 
 {
     aimAnimInstance = this;
 }

 void Update ()
 {
     Aim ();
     Shoot ();
     Reload (); 
     Die ();
 }

 void Aim ()
 {
     if ((Input.GetMouseButtonDown(1)) && (IsAiming == false) && (isReloading == false)) 
     {
         GetComponentInChildren<Animation> ().Play ("Rocket_Aim");
         IsAiming = true;


     } 
     else if ((Input.GetMouseButtonDown(1)) && (IsAiming) && (isReloading == false)) 
     {
         GetComponentInChildren<Animation> ().Play ("Rocket_AimOut");
         IsAiming = false;
     }
 }

 void Shoot () 
 {
     if (Ammo > 0) {
         hasAmmo = true;
     } 
     else 
     {
         hasAmmo = false;
     }
     if (MaxAmmo > 0)
     {
         if ((Input.GetMouseButtonDown (0)) && (hasAmmo) && (isReloading == false)) 
         {
             Instantiate (bullet, spawnLocation.transform.position, spawnLocation.transform.rotation);
             Ammo--;
             MaxAmmo--;

             GetComponent<AudioSource>().PlayOneShot (shootSound, 1f);
             GetComponentInChildren<Animation> ().Play ("Rocket_Recoil");
         }
     }
 }

 void Reload () 
 {
     if (isReloading) 
     {
         reloadAnimTime -= 1 * Time.deltaTime;
         if (reloadAnimTime <= 0) 
         {
             isReloading = false;
             reloadAnimTime = reloadTime;
         }
     }

     if ((Ammo < 1) && (MaxAmmo > 0)) 
     {
         canReload = true;

         if ((Input.GetKeyDown (KeyCode.R)) && (canReload)) 
         {
             GetComponentInChildren<Animation> ().Play ("Rocket_Reload");
             IsAiming = false;
             isReloading = true;

             Ammo++;
         }
     }
 }

 void Die ()
 {
     if (Health <= 0) 
     {
         isDead = true;
         print ("Player died");
     }

     if (isDead) 
     {
         Application.LoadLevel ("Die_Scene");
     }
 }

 void OnTriggerEnter(Collider col) 
 {
     if (col.gameObject.tag == "R_Pickup") 
     {
         isPickedUp = true;

         if (isPickedUp) 
         {
             Destroy (gameObject, 0.7f);
             GetComponent<AudioSource> ().PlayOneShot (pickSound, 1f);
             AimAnim.aimAnimInstance.MaxAmmo++;
         } 
         else 
         {
             isPickedUp = false;
         }
     }
 }

}