Roots look great. I'd look into up-potting this banana. As for the leaves, they look dry... I'm guessing you brought your banana indoors for the Winter? Keep in mind indoor weather is much dryer.... especially with the heater on. Try to increase the humidity. Also, I'd leave the leaves on until they dry to a crisp(brown and shriveled) so the plant can suck back as much energy as possible.

Thank you so much Dave. It's been indoors all along. It's been doing fine all summer and fall. It went into sudden decline about ten days ago without any change in circumstance that I'm aware of.

Indoors is no place for a banana plant. so ,decline is normal. They need plenty of light. If you are living in the north it could be from many grey days and a little too much water. Let it go dry a bit in between watering. Whatever you do don't re pot it until the spring (April or May).