The collision was one of the worst in living memory.
We launched a comprehensive investigation immediately after to establish the full circumstances which led to the collision.
Our investigation was meticulous and complex. We took hundreds of witness statements, examined 34 vehicles and consulted several experts, including meteorologists, pyrotechnic and forensic specialists.
Based on this evidence the Crown Prosecution Service took a decision to charge. However, following further consideration in recent weeks they have decided to discontinue the manslaughter charges.
More top news
The Met Office has issued a yellow 'be aware' weather warning of ice for parts of Wales overnight and into tomorrow morning.
A report says that sex and relationship education in Wales is too focused on biology.
The FAW CEO is to face a disciplinary hearing over a comment he made relating to Wales' next manager not being English.