Can I access children's colliders from the parent?

Hi guys I’m trying to do a 2d-game where it uses tetris shapes. I’m having problems with the collision. And this is what i did.

  1. Create a cube. Set size to be 64x64. Check (tick/enable) the “IsTrigger” in box collision.

  2. Create a empty game object and drag the cube into this empty game object

  3. Copy the cube and creates 3 other instances of that cube. Arrange it to make an inverted “L” shape.



← gameobjects position.

Now i want to make it such that the box collider follows this inverted “L” shape. How do i do that? Oh and here is my script which i attached to my gameobject

// Update is called once per frame
	void Update () {
		// if falling is allowed
		if (m_bIsFalling)
		{
			Fall();
		}
		
	}
	
	void Fall()
	{
		this.transform.position = new Vector3( this.transform.position.x, this.transform.position.y - Falling_Speed, this.transform.position.z );
	}
	
	void OnTriggerEnter(Collider other)
	{
		if (other.gameObject.tag == "Ground" || other.gameObject.tag == "Wall")
		{
			this.transform.position = new Vector3(other.gameObject.transform.position.x ,this.transform.position.y, this.transform.position.z);
			m_bIsFalling = false;
		}
	}

which was initially attached to each individual cube with this code instead:

// Update is called once per frame
	void Update () {
		// if falling is allowed
		if (m_bIsFalling)
		{
			Fall();
		}
	}
	
	void Fall()
	{
		this.transform.Translate(new Vector3( 0, - Falling_Speed, 0 ) );
	}
	
	void OnTriggerEnter(Collider other)
	{
		if (other.gameObject.tag == "Ground" || other.gameObject.tag == "Wall" || other.gameObject.tag == "TPBlock")
		{
			this.transform.position.Set(other.gameObject.transform.position.x ,this.transform.position.y, this.transform.position.z);
			m_bIsFalling = false;
		}
	}

I also tried using fixed hinges to make the 4 cubes act as 1 object but that failed miserably. Can anyone help me here? Any help is appreciated. Thanks in advance.

This works thanks!

using UnityEngine;
using System.Collections;

public class TetrisPeopleBlock : MonoBehaviour {
	// the speed of which the tetrispeople block falls
	public float Falling_Speed;
	[HideInInspector] public bool m_bIsFalling;

	// Use this for initialization
	void Start () {
		m_bIsFalling = true;
		Falling_Speed = 2;
	}
	
	// Update is called once per frame
	void Update () {
		if (m_bIsFalling)
	    {
	    	Fall();
	    }
	}
	
	void Fall()
    {
    	this.transform.position = new Vector3( this.transform.position.x, this.transform.position.y - Falling_Speed, this.transform.position.z );
    }	
	
	void OnTriggerEnter(Collider other)
	{
		print("hit");
		m_bIsFalling = false;
		
		foreach(Transform sibling in transform.parent)
		{
			TetrisPeopleBlock script = GetComponent<TetrisPeopleBlock>();
			
			if(script != null)
			{
				script.m_bIsFalling = false;
			}
		}
	}
}