How long did the Aberfan disaster go on for?

The initial slurry slide started at approximately 09:00 It moved down hill toward the school taking out a farmhouse in its path. At 09:15 the slurry hit the school and nearby house and drove through the buildings. The slurry slide continued for several hours with rescuers continually attempting to divert as much as possible. This hindered many of the rescue attempt. However, slurry was still moving in to the main area of the disaster days later