Reread Johns post. If its green (wet) wood, turn it 90% and even thickness and then set aside to dry (there have been numerous posts here on this, do a search). Re-turn when dry. If dry, you shouldn't have any cracking problems.
I'm just guessing, but I'll assume you're relatively new to turning? If so my advice to all new turners is to take a class, join a club, or find a more experienced turner to mentor you (or all of the above).
That bowl was perfect right up until that last cut...