Hundreds of people have attended a ceremony to mark the centenary of the West Stanley Pit Disaster in which more than 160 miners died.
A service was held on the site where the explosion took place in 1909.
At 1545 GMT on Monday - the exact time of the explosion - the bells of St Andrews Church rang out 168 times to remember the 168 victims.
Up to 200 people paid their respects at the service organised by Derwentside District Council.
A spokesman for the council said: "It was a huge disaster and should not be forgotten - the youngest victim was 14 years of age and men and boys died.
"The bells will ring 168 times to remember every single victim."