Left car sunroof open in the rain. Now it won't start!?

I did a really stupid thing. Left sunroof open on my 2008 Infiniti FX35 at night. It rained about 2' overnight. Nothing turns on in the morning (good thing I also left the doors unlocked). There is no voltage left on the battery, so I tried to jumpstart it from another car. The electrical system seems to come on, but the car won't start. It just cranks. What are the possible problems. Help!!!