The official opening was planned for 29 June with great public festivities, however on 9 June part of the ground at the south west corner of the lock sank , leaving the concrete facing unsupported. At the same time, a strip of earth at the back of the lock on the north side sank, carrying with it, two steam traction engines which had been used for pumping. They were buried deep in the silt. Frantic efforts were made to repair the damage. Trainloads of sand, silt, rubble, clay and limestone were poured into the gaps to no avail. On the following Tuesday of concrete facing on the opposite, west side of the dock itself were dislodged because the footings had been scoured away. On Wednesday, many more yards of the concrete cracked and subsided. All three ships which had been in the dock had got away safely with some difficulty. The great weight of concrete laid on shifting silt, together with inadequate timber piling would appear to have led to the collapse. Efforts to save the dock were soon seen to be futile and the plan was abandoned. The railway company lost a fortune and Sutton Bridge's growth as a port was halted for over 100 years.