Flat out refusal

We were more than half-way across the pedestrian bridge when Tessa realized she was crossing water on wooden planks. And panicked. For more than 20 minutes she refused to move forward or backward. After an incident last winter, where she fell off a boat pier into the river, she refuses to go onto the docks, or wooden bridges. Today, I almost had her fooled. But not quite. Passers-by either laughed or sympathized, but no one could help. She could not be enticed with treats. I practically had to carry her back the way we'd come - and she's a VERY heavy puppy!