Today marks the 60th anniversary of the Windscale fire - the worst nuclear accident in British history.
On Thursday, October 10 1957, the 400ft pile at the Windscale works caught fire and burned for three days.
The twin Windscale piles had been producing plutonium in top secret as part of Britain's atomic bomb project.
The fire spread radiation across the UK and Europe, which was eventually responsible for around 240 cases of cancer.
It's thought that around 100 of those cases were fatal.
There was an immediate ban on the distribution of milk from an area covering 200 square miles.
Neither of the Windscale Pile reactors ever worked again.
It ranked at severity level 5 out of 7 on the International Nuclear Event Scale.
Anti-nuclear campaigners are expected to lay flowers outside the site today.