RedactedNarrative: Vessel number 1 was dismasted after hitting a rail bridge.  Vessel number 2 attempted to assist vessel 1 that was drifting toward some rocks on the bank of the river.  Vessel number 2 passed the line to another boat who started to tow vessel 1.  Vessel 1 had little steering ability due to the mast laying over the tiller and rudder assembly.  When vessel 3 moved along more of a straight line than anticipated, it struck vessel 2 on the port side and the passenger on the left arm.