This sketch shows the river locked tight with ice. Just as I finished, the ice started moving — creaking, groaning, banging, cracking, slurping and sloshing, MOVING ON. Incredible event to witness. I was alone for a long time, sketching, but people were stopping on the bridge to check as they drove through; when it actually let loose, I was there all alone. Potential energy turning back into kinetic energy. Powerful!