Minecraft crashed

Put the summary of the bug you're having here

What I expected to happen was...:
I turned on my computer and clicked on the minecraft icon to get back onto minecraft so i would be able to play it without it crashing again.

What actually happened was...:
I clicked on the minecraft icon to get back on and the minecraft launcher 1.2.1 said that the game has crashed.

Describe what happened here

Steps to Reproduce:
1. Minecraft froze on me so I shut my computer off.
2. I turned my computer back on and tried to get back on minecraft.
3. The minecraft launcher 1.2.1 said the game crashed.