Game Over page score is always 0

I’m following Mike Geig’s infinite runner tutorial but even though the scripts are identical my game over page always says 0 as the score and I don’t know why.

this is the game over script where I think something might be wrong

using UnityEngine;
using System.Collections;

public class GameOverScript : MonoBehaviour {
	
	int score = 0;

	void Start () {
		score = PlayerPrefs.GetInt("score");
	}

	void OnGUI()
	{
		GUI.Label(new Rect (Screen.width / 2 - 40, 50, 80 ,30), "Game Over");

		GUI.Label(new Rect (Screen.width / 2 - 40, 300, 80, 30), "Score: " + score);
		if(GUI.Button(new Rect (Screen.width / 2 - 30, 350, 60, 30), "Retry?"))
		{
			Application.LoadLevel (0);
		}
	}

}

You are getting “score” and setting “Score”. Strings are case sensitive, so these two variables are different.