What would island of adventures do on a Rainy day?

My friends were at Islands of Adventure for a band trip, and it rained while they were there and they told me many of the people started to leave when it rained, and most of the outdoor rides were closed, but they still did a lot of Indoor rides, like the new Harry Potter and the Forbidden Journey. The 4th of July will be busy, because it is a theme park and a holiday, but I have never been, but have been rained out of many parks like Busch Gardens and Disney's Animal Kingdom. the indoor rides will be open, but the outdoor coasters and such will probably be closed.