A 1981 Weldcraft was north bound on the Snake River near the Interstate Bridge.  The operator either by inattention or contributing medical conditions, struck the third suspension pier of the bridge from the Idaho side.  A passenger in the vessel was thrown forward in the vessel where he struck the infrastructure and was momentarily stunned.  The passenger said he tied the boat to a piece of metal framework on the bridge and went back in the boat to help the operator who had been unconcious.  The passenger said the operator was now awake, but pinned in the vessel and he was unable to get him out.  The passenger said that the boat sank and he swam to the surface.
Lewiston                      