The third chick had hatched when I checked them this morning. It's the one at the back with its head facing us. As each chick hatches it makes it really obvious how much the prevous chicks have grown. As you can see, chick 1 is now a little fatty!
Just incase you can't work out what on Earth is going on in the first photo, here's the edited version! Chick 2 was hiding from the camera to make the pile of babies look even more confusing.