Hmmm... that looks bad. Following WhiteRabbit's advice might work but most likely the plant is goner. Get yourself new one and keep your fingers crossed for the old one.
I will, thank you, btw how do I prevent this from happening again?
it's likely there was water sitting in the crown ... try to avoid getting water in the crown, if you do, use the corner of a paper towel to soak it up. Or use a straw to blow water out.