All Speakers Suddenly Stopped Working -- Honda Odyssey 2002

While driving, all of the speakers in my Honda Odyssey suddenly stopped working. There was a very soft "thud"-like sound, an electric smell, and all sound went out immediately. The stereo unit itself still comes on and the screen and all of the buttons work as expected -- but no sound comes out of any of the speakers.

Any ideas and guidance would be so appreciated!
What might cause this?
Is there an easy fix I might be able to pull off myself -- or with some help??
Thank so much!