boston & maine 4-6-2 class p2b

Does anyone know of a weblink to a picture of this type of engine? I’m also interested in a particular engine: #3666. I’ve heard that for some reason this engine was actually thrown into the harbor of Portsmouth, NH. Some people claim to have seen photos of this engine sitting in the mud on the bottom. Anyone have any photos of that?

I remember reading about steam loco and train crossing a harbor on a train ferry, the air brakes failed/were not set correct and the whole train actually rolled off the ferry into the water. I beleive this might have been in Boston Harbor but my memory is vague on this.

Could it be the same train?