The Albion was a battleship built by the Thames Ironworks and Shipbuilding Company (TIASC) at Blackwall. The launching attracted huge crowds and, in spite of warnings that it was dangerous, some 200 people crowded on a flimsy bridge structure in order to get a better view. The Duke and Duchess of York (later King George V and Queen Mary) were in attendance. Bad luck loomed when the Duchess failed three times to smash a bottle of champagne to start the launch, before resorting to cutting a cord. As the ship slipped into the river it created a large wave which engulfed the bridge, plunging onlookers into the water. The cheers of the main crowd still applauding the launch drowned out the cries of those floundering in the river, thus delaying the start of the rescue operation. Sources differ as to the total number of fatalities, ranging from 34 to 39.
More details of the incident at Find a Grave.
R. W. Paul's film of the launch and the subsequent rescue operation (or the tail end of it) is a very early piece of disaster reportage. There is a point at which we think you see the ship already launched but no recognition of anything amiss.
TIASC's works straddled the mouth of Bow Creek near its confluence with the River Thames, at Leamouth Wharf. Two 1900 Goad insurance maps show the site: the south side, 'Orchard Yard', and the north side, with a 'private ferry' connecting them. The north side shows the 'slips' and a 'gangway' which could easily be part of the structure which gave way. This is surely where the disastrous launch took place, immediately north of what Google Maps currently (2023) has marked as 'Trinity Buoy Wharf'.
At Royal Navy we learnt that this HMS Albion was the 5th ship so named, and in 2021 sailors from the current ship (7th with the name) visited the mass grave at the cemetery.