How do I get rid of the drooping orangey leaves on my magnolia tree?

I have a large magnolia tree in my front yard and another that is slightly smaller in the backyard. The one in the front yard has drooping leaves that are turning orange/yellow and falling off. The tree looks like it still may have buds for blooms but I can't see them very well as this tree is very tall. What could be the problem with my leaves and how do I make this tree healthy looking again?