A red plaque has been unveiled at the site where five firefighters and one civilian were killed in an explosion fifty years ago.
The Dudgeon's Wharf disaster killed more firefighters than any other single event in London since the Second World War.
Firefighters Michael Gamble, Alfred Smee, John Appleby, Terrance Breen and Trevor Carvosso, and construction worker Richard Adams, were all killed when an oil tank exploded on the Isle of Dogs in 1969.
When fire broke out in the tank firefighters were called. But as they had no idea what the tanks contained, and no warning of the dangers, an order was given for a demolition worker to cut through the bottom of the tank to allow further access.
It is thought a spark from the cutting equipment, combined with the flammable vapours inside, led to the fatal explosion.
As a result of the explosion the Hazchem Code was introduced in the 1970s, to make sure hazardous materials are properly labelled.
Fireman Terrance Breen's son Terry, who was five when his father was killed, said:
The Brigade's Assistant Commissioner Andy Roe said: