Index out of range exception - C# - Can't find the problem

I can't find the problem in this code. It always says that my Array index is out of range.

I have 2 scripts:

 using UnityEngine;
 using System.Collections;
 
 public class World : MonoBehaviour {
     
     public static World currentWorld;
     
     public int chunkWidth = 10, chunkLength = 10, chunkHeight = 0, seed = 0;
 
     // Use this for initialization
     void Awake () {
         currentWorld = this;
         if (seed == 0)
             seed = Random.Range(0, int.MaxValue);
     
     }
     
     // Update is called once per frame
     void Update () {
     
     }
 }

And this one:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class Chunk : MonoBehaviour {
     
     private Vector3[,,] map;
 
     MeshRenderer meshRenderer;
     MeshCollider meshCollider;
     MeshFilter meshFilter;
     
     public GameObject prefab;
 
     // Use this for initialization
     void Start () {
         
         meshRenderer = GetComponent<MeshRenderer>();
         meshCollider = GetComponent<MeshCollider>();
         meshFilter = GetComponent<MeshFilter>();
         
         map = new Vector3[World.currentWorld.chunkLength, World.currentWorld.chunkHeight, World.currentWorld.chunkWidth];
         
         for (int x = 0; x < World.currentWorld.chunkLength; x++)
         {
             for (int z = 0; z < World.currentWorld.chunkWidth; z++)
             {
                 Instantiate (prefab, map[x, 0, z], Quaternion.identity);
             }
         }
     }
     
     // Update is called once per frame
     public void CreateVisualMesh () 
         {
 
         }
 }

Any help is appreciated.