Minecraft froze mid game! (Mac)?

I was just playing Minecraft on a server and went to open a chest and it froze up on me. I didn't create like a ton of stuff to cause it to freeze i Don't know why it happened. When i try to force a shutdown it won't let me saying to "Quit Minecraft" then there a pop up saying to quit it but i just won't quit! After trying multible time. I can't really fore shut down my computer because of it some1 help please!