Read somewhere that she lost steering.
In order to maintain steering, the ship must have headway. In square riggers, this is provided by staysails (triangular sails that run parallel to the long axis of the ship) and perhaps a foretopsail (a square sail on the forward mast that runs perpendicular to the long axis of the ship). However, the picture appears to show bare poles, i.e. the sails were not fixed to the yardarms. If true, that means that they were relying entirely on diesel engine power to keep her underway and power the pumps. Once they lost that, they couldn't keep the bow pointed into the waves.